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26 Case Examples This chapter contains four case examples of North American transit agencies that responded to the survey and use ITS technologies for some degree of monitoring and control of headway-based operations. The synthesis team contacted selected case example agencies and arranged an interview conducted by web conference. Some agencies also shared internal documentation related to HBS and ITS. In this chapter, meetings with transit agency staff are not cited as sources. This chapterâs case examples are organized as shown in TableÂ 14, which summarizes each agencyâs key operating statistics. City and County of Honolulu Department of Transportation Services Introduction The City and County of Honolulu Department of Transportation Services is the transit agency for Honolulu County, Hawaii, which covers the entire island of Oahu. TableÂ 15 summarizes the agencyâs modes and operating statistics. Bus (TheBus) and demand response (TheHandi-Van) are operated by Oahu Transit Services, Inc., under a public-private partnership. The information contained in this case example was provided by Oahu Transit Services. TheBus was selected as a case example because it represents a mid-size city with high density and ridership. In addition, the agencyâs survey responses indicated that it had recently imple- mented HBS, had an implementation motivated by service problems, and uses a wide range of ITS technologies and control strategies. Operating Context TheBus operates two routes by headway: â¢ Route 8 runs between Waikiki and the Ala Moana shopping center. Waikiki is the main tourist area of Honolulu, and the route serves a highly developed area with many hotels. The route is fairly short, 30Â minutes or less from end to end. The span of service is from approximately 8:00Â a.m. to 10:00Â p.m., and the route is operated by headway at all times. â¢ Route 2 has the highest ridership in TheBusâs system and runs between Waikiki and the Kalihi Transit Center via downtown Honolulu. The route serves a highly developed tourist area, the central business district (CBD), and urban neighborhoods. The route is fairly high density C H A P T E R 4
Case Examples 27Â Â throughout and serves a mix of tourist and commuter demand. It runs 24Â hours a day but is only operated by headway from 8:00Â a.m. to 5:00Â p.m. on weekdays. Both routes are operated with regular buses and do not have any branding to distinguish them from other routes operated by schedule. System Development TheBus first conducted a pilot test of headway-based operation on Route 8. The company that supported the pilot test went out of business, which prompted the development of the current system for full implementation. Route 8 was converted to headway-based operation first, around the end of 2018 and beginning of 2019. Headway-based operation was then deployed on Route 2 in mid-2019. Motivation The deployment of headway-based operation on the two routes was motivated by different factors. Route 8 is a circulator that overlaps with several other routes in Waikiki. Route 8 also has a relatively large fleet because of its high frequency. As a result, Route 8 buses are treated some- what like stage vehicles by dispatchers. If a bus on another route breaks down, then one is taken off Route 8 to replace it. Sometimes one or two buses are taken off Route 8 depending on the day. A key objective of headway-based operation was to make it easier to rebalance Route 8 after a bus is removed or inserted. Route 2 is longer than Route 8 and also has many buses due to its high frequency. The route had recurring problems with bus bunching, and the main goal of headway-based operation was to address these service problems and maintain regular spacing. Intelligent Transportation Systems TheBus uses TransitMaster, a CAD/AVL system developed by Trapeze. All ITS technology that supports headway-based operation was already installed as part of TransitMaster. One Case Example Agency Region Bus Peak Vehicles Year Headway- based Operation Implemented Headway Routes City and County of Honolulu Department of Transportation Services Honolulu, HI 455 2018 2 Capital Metro Austin, TX 312 2014 2 LA Metro Los Angeles, CA 1,750 2011 1 King County Metro Seattle, WA 1,015 Pre-scoping 0 Source: National Transit Database 2018. Table 14. Case example agency key operating statistics. Mode Unlinked Passenger Trips Vehicles Operated at Maximum Service Bus 17,933,771 455 Demand response 1,162,606 235 Demand responseâtaxi 213,166 115 Vanpool 25,386 12 Source: National Transit Database 2018. Table 15. City and County of Honolulu Department of Transportation Services key annual operating statistics by mode.
28 Intelligent Transportation Systems in Headway-Based Bus Service notable piece of equipment is the MDT, which provides information to bus drivers. The software used for HBS was developed by Trapeze as a module for TransitMaster. TheBus received the software at no additional cost (beyond the prior ITS installation costs and existing ITS support contract) and supported the module development by serving as a beta tester. Collaborations with Stakeholders As noted previously, TheBusâs routes are operated by Oahu Transit Services as a public- private partnership with the City and County of Honolulu Department of Transportation Services. TheBusâs operations control center has a feed into the city/countyâs traffic camera system, and bus dispatchers (referred to as central controllers) can turn and move the cameras if needed. The City and County of Honolulu has recently upgraded to a new traffic management center. TheBus expects more integration between traffic management and bus operations in the future, such as back-end connections between the two centers. However, there are no specific plans at the moment. TheBusâs central controllers monitor other alert systems that may impact bus operations (e.g., incidents, weather, and public health) through normal channels. This monitoring is passive, and there are no specific collaborations or back-end connections with the State of Hawaii, National Weather Service, or other sources of information. Operations Normal Procedures and Driver Training All buses are equipped with an MDT, and drivers are responsible for checking the MDT and following the prompts the same way they would follow a paper schedule. Generally, the prompts are updated every 45 seconds and have both a numerical and color component. Ideal spacing is defined as a 3-minute window, ranging from 1Â minute ahead to 2Â minutes behind the headway target. If the bus is more than 1Â minute ahead, the MDT shows a positive deviation and a red background. If the bus is within the ideal window, the MDT display is yellow, and if it is more than 2Â minutes behind, the deviation is negative and the background green. TheBus notes that drivers often have a hard time adapting to headway-based operation. Some like to drive for a while without looking at the MDT, which creates more problems in headway- based operation than in schedule-based operation. Central controllers can call drivers or send text messages to their MDT. Some drivers stay on Route 2 or 8 all day, while others operate runs on both headway- and schedule-based routes. Most drivers have experience with HBS now. TheBus has various mini-training sessions for drivers, which last 18Â minutes and take place before or after a regular shift. Drivers attend a session on HBS before they operate a headway run for the first time. The control center also talks to first-time drivers to explain the procedure. Control Actions TheBus uses several operational control strategies in HBS: boarding limits, holding, short turns, speed guidance, and stop skipping. Boarding limits and stop skipping are activated when a bus reaches capacity, generally 65 passengers or when there is no more room for passengers to board and move behind the yellow line. Holding and speed guidance are practiced by drivers in response to MDT prompts. Reducing speed is generally preferred to holding, but drivers have some discretion in how they carry out MDT instructions. The objective used by the underlying software is to regularize headways on the route. The system determines the target headway by calculating the cycle time and dividing
Case Examples 29Â Â by the number of buses. In practice, this means that the exact headway target varies based on the number of buses in service as well as real-time passenger demand and traffic conditions. Short turns are most commonly practiced at the end of the line. Central controllers can change the order of buses, for example instructing a second arriving bus to turn around immediately while the first holds at the terminus. Headways are calculated by the CAD and MDT systems based on real-time position, so the order of buses is switched automatically if one bus passes another anywhere on the route. Removing Buses The system allows for a bus to be removed from service, a procedure that is termed quarantining. Once the bus is removed, the system will try to redistribute all others on the route to return to even spacing. Drivers notice when this happens because their MDT guidance changes rapidly. Relief An issue in headway-based operation is that the location of a bus at a planned driver relief time varies depending on the day. On Route 8, TheBus used to switch all drivers at the western end, Ala Moana, but has now added several street relief points along the route. Drivers switching in check the current location of their bus and are then shuttled from the depot to the closest street relief point. On Route 2, the relief point for all drivers remains at the bus facility. Buses have an adher- ence schedule that is generally ignored during the hours of headway-based operation but does determine when drivers begin and end their shifts. TheBus found that drivers often speed up toward the end of their shift in order to keep the adherence schedule and get off work on time. Since this behavior is undesirable in headway-based operation, TheBus now tries to keep Route 2 buses slightly ahead of their adherence schedule. Updates TheBus updates schedules every 3Â months. The number of buses assigned to Routes 2 and 8 has not changed since the deployment of HBS. TheBus considers the flexibility of headway- based operation to be a great advantage. It is not necessary to rewrite a schedule to change service levels, and buses can be added or subtracted as needed. TheBus has used this property of the system to dynamically adjust service levels during the COVID-19 pandemic in order to keep bus occupancies at a level that allows for safe social distancing on board. Performance Monitoring TheBus uses three performance measures for headway-based routes: â¢ Headway adherence, â¢ Number of trips, and â¢ Pass-up complaints. The full implementation of HBS is recent, and TheBus is still working on performance measurement. On schedule-based routes, adherence is defined as Â±3Â minutes. Because head- ways depend on the position of other buses, a procedure had to be developed to playback bus positions and calculate headways. The number of trips is included in performance monitoring to track the amount of service provided. A problem that TheBus found in the pilot test was that it slowed buses down, increasing cycle times. The current system dynamically adjusts the target headway, which can be shorter than the scheduled headway at times. This feature has eliminated the drop-off in the number of trips. This measure also captures the impact of missed trips due to breakdowns and staffing issues.
30 Intelligent Transportation Systems in Headway-Based Bus Service The third measure tracks passenger complaints. Pass-ups were common on Route 2 before the deployment of HBS. Sometimes buses get overloaded, even with headway control. TheBus analyzes complaints to identify the cause. For overloading, usually the reason is a spacing issue that causes a bus behind a large headway to pick up more passengers. Central Controllers TheBus does not have dedicated controllers for HBS. Central controllers typically monitor 10 to 12 routes each, although some are small. Route 8 has seven or eight buses all day long, and then the number drops in the evening. Route 2 has 18 to 20 buses, increasing to 24 in the after- noon peak. Most issues are with drivers failing to check and adhere to the MDT. TheBus has developed training for control center personnel to explain HBS. Strategies have evolved since the initial deployment. There is also a handout for controllers that explains how to use the system, dashboard, and procedures specific to HBS such as quarantining (removing) a bus and switching the order of buses. Summary TheBus operates two routes by headway: Routes 2 and 8. Route 8 is a circulator between Waikiki and Ala Moana and serves a significant amount of tourist traffic. Route 2 is a busy commuter route that serves Waikiki, the Honolulu CBD, and urban neighborhoods. Headway- based operation started with a pilot test on Route 8 and was fully implemented in late 2018 and early 2019, extending to Route 2 about 6Â months later. The main strategies used to maintain headways are speed guidance and holding. Both are determined by drivers, who see their real-time headway deviation and a color-coded back- ground (red means ahead, yellow means on target, and green means behind) on their MDT and are expected to make the appropriate adjustments. Short turns are sometimes used at the terminals to change the order of buses. These changes are initiated by central controllers. Board- ing limits and stop skipping are used when a bus reaches capacity but primarily to prevent overcrowding. TheBusâs headway-based routes are well integrated with the rest of the bus system. Vehicles, drivers, central controllers, and the CAD/AVL system are all common to both headway- and schedule-based service. Drivers receive headway and schedule adherence prompts in the same way on the MDT. In terms of the key elements of ITS, the key elements are the MDT installed in the driver cabin on all buses, the CAD/AVL system, and the software module that updates the headway targets and deviations. Challenges TheBus noted that the main challenge in operating HBS is driver compliance. Nearly 1,000 drivers work for the agency and are all expected to be able to operate a headway run if needed. Some drivers do not agree with the MDT prompts or do not follow them. Headway adherence can also change rapidly (especially if a bus is inserted or removed), which may surprise drivers who are used to schedule adherence. A limitation of the current system is its ability to cope with different service patterns. Routes 8 and 2 operate a single service pattern for most of the day, but there is a limited-stop Route 2 during the morning peak. TheBus and Trapeze have developed a software package to integrate normal and limited-stop services, but there is still room for improvement. The regular and limited-stop services on Route 2 tend to depart from the terminus at regular spacing, and then the limited-stop buses pass regular buses along the route.
Case Examples 31Â Â Notable Practices One notable practice is the role that Route 8 buses play as stage vehicles that can be inserted onto other routes if needed. This practice was a key motivation for converting Route 8 to headway-based operation. Stage vehicles are a common practice discussed in the literature and used by other transit agencies. A common concern, however, is the cost of keeping a driver and vehicle on standby outside revenue service. TheBusâs approach avoids this problem entirely by keeping the stage vehicles in revenue service until they are needed. TheBusâs system dynamically adjusts the target headway by estimating the current cycle time on the route and dividing by the number of buses in service. This method is robust to various disturbances, including incidents or weather conditions that delay all buses, spikes or drops in passenger demand, and addition or removal of buses. TheBus mentioned that this feature of the headway control software has been effective on Routes 2 and 8 and is now being considered as a strategy to recover from major service disrup- tions on other routes. Incidents that slow down all buses, such as a big accident on the freeway, delay all buses and render the adherence schedule unattainable. Headway-based operation can be switched on and off at the control center, so normally schedule-based routes could be operated by headway until they recover or reach the end of service. Dynamic adjustment has also been useful in responding to the COVID-19 situation, which has caused a large drop in ridership. TheBus has been able to adjust service levels on the fly to keep bus occupancies at acceptable levels, without having to manually set a target headway or write a new schedule. The same principle could be used in the future to respond to other changes in passenger demand, such as major events or busy tourist periods. Lessons Learned TheBus emphasized that headway-based operation ultimately depends on the drivers. Making sure that drivers understand the system and getting them to buy in are key to successful headway- based operation. Close oversight is important, and there needs to be a lot of interaction between central controllers and bus drivers, especially for drivers that are new to HBS. New drivers can also benefit from a discussion with their supervisor before or after the shift to make sure that they understand the system and are taking the appropriate actions based on the MDT prompts. Capital Metropolitan Transportation Authority Introduction The Capital Metropolitan Transportation Authority (Capital Metro) is the transit agency for the Austin region in Texas. Its service area includes the city of Austin as well as several adjacent cities and portions of surrounding counties. TableÂ 16 summarizes Capital Metroâs modes and operating statistics. Mode Unlinked Passenger Trips Vehicles Operated at Maximum Service Commuter bus 613,852 35 Bus 26,879,274 312 Demand response 675,564 154 Hybrid rail 811,242 7 Vanpool 511,337 250 Source: National Transit Database 2018. Table 16. Capital Metro annual operating statistics by mode.
32 Intelligent Transportation Systems in Headway-Based Bus Service Capital Metro is organized as a public agency with a board of directors including repre- sentatives appointed by the regionâs metropolitan planning organization, the Austin City Council, and county commissioners in the two immediately adjacent counties. One member represents smaller cities within the service area. All transit services are operated by contracted service providers (purchased transportation), including Capital Metroâs two headway-based MetroRapid bus lines, which are the focus of this case example. Capital Metro was selected as a case example because it represents a mid-size city in the southern United States, uses a wide range of ITS technologies and control strategies, and has multiple routes managed by headway. The MetroRapid routes often operate in mixed traffic, challenging headway management. In addition, Capital Metro has been operating the MetroRapid routes since 2014, providing significant experience operating HBS. Operating Context Capital Metro operates two routes by headway under the service name MetroRapid: Routes 801 and 803. Both MetroRapid routes have some BRT features such as high levels of service, TSP, all-door boarding, limited stops, some queue jumps, and portions of the route that operate in dedicated bus-only lanes. Routes 801 and 803 are roughly north-south routes and share a corridor and 14 stations from north Austin through downtown. However, outside of downtown, the routes separate and run to different northern and southern termini. Both routes travel from largely suburban termini and pass through downtown along key, high-demand corridors in the Austin region, serving several significant locations like the University of Texas at Austin, the state capitol complex and many state offices, and Austinâs CBD. Route 801 is 22Â miles long with 29 stations and runs from the Tech Ridge Park and Ride in the north to the Southpark Meadows shopping center in the south. Route 803 is 16Â miles long with 27 stations and runs from the Domain in the north to the Westgate Transit Center in the south. FigureÂ 5 shows both routes on the map (not to scale). The MetroRapid routes are equipped with TSP at most intersections and use a dedicated bus lane in the downtown area between Martin Luther King Jr. Boulevard and 3rd Street. The south- bound dedicated bus lane runs for 1Â mile along Guadalupe Street, and the northbound dedicated bus lane runs for 1Â mile along Lavaca Street between 18th St. and 3rd St. Many other bus routes also use these dedicated bus lanes, and on some blocks, the bus lane is also a right-turn lane. The MetroRapid stations are sometimes separated from other bus stops but not always. Stations have high-quality cantilevered shelters with real-time passenger information and often full-size MetroRapid, transit system, or local street maps. The MetroRapid buses are branded differently from other Capital Metro buses, and MetroRapid-branded buses are capable of operating on either MetroRapid route. However, Route 801 typically uses 60-foot articulated three-door buses, especially during heavy ridership times of day. Route 803 typically uses 40-foot two-door buses. Passengers can board at all doors on a MetroRapid bus to facilitate faster boarding. However, passengers paying cash or buying a pass must use the front door. Rear doors are equipped with a QR code reader to read mobile tickets and a magnetic stripe reader to read passes. The MetroRapid routes are typically both in the top five routes by ridership in Capital Metroâs bus system, with Route 801 usually being number one and typically carrying over 250,000 monthly riders (pre-COVID). Route 803 typically carries between 150,000 and 160,000 monthly riders (pre-COVID) (Capital Metro 2020a).
Figure 5. Map of the 801 and 803 MetroRapid bus routes (Source: Capital Metro 2019).
34 Intelligent Transportation Systems in Headway-Based Bus Service System Development The MetroRapid routes were approved for implementation by the Capital Metro board in AugustÂ 2004 as BRT routes. Both routes run as overlaid service along corridors served by their heavily used predecessors. Route 801 runs generally in the same corridor as local Route 1, and Route 803 runs generally in the same corridor as local Route 3, with the local routes making many more stops. The MetroRapid routes were designed to improve service quality and speed for the large number of riders using transit in these respective corridors. (Routes 1 and 3 continue to run in generally the same corridors as prior to the implementation of the MetroRapid routes.) The MetroRapid routes were designed to be operated by headway and included several features in their design to assist in headway-based operations: a dedicated lane in the downtown area, TSP, a limited number of stations, and all-door boarding. In terms of ITS, Capital Metro has AVL, CAD, APCs, EFP, PIS, onboard cameras, a smartphone app, and TSP. All features except for PIS and TSP are common to all bus services provided by Capital Metro. As previously mentioned, the MetroRapid routes operate in mixed traffic and in corridors served by other bus routes, especially in the downtown area. Capital Metro has discussed operating other bus routes by headway and has a frequent transit network (FTN) of routes that operate with 15-minute or better headways seven days a week (with 20- to 30-minute headways in the morning and late evening). If headway-based operations were expanded to other routes, the FTN routes would likely be the ones to switch to headway-based operations. However, many obstacles remain that make it difficult to switch to headway-based operations for all FTN routes: â¢ All routes operate in mixed traffic for most of their alignments, making managing headways difficult. â¢ Only the MetroRapid routes are currently configured to use TSP. â¢ Only the MetroRapid stations currently have real-time arrival signage (although real-time arrival information is available to all through Capital Metroâs real-time information suite, including mobile app(s), text messaging, and call-in). â¢ Even with all the priority treatments the MetroRapid routes have, managing headways on the routes has and continues to be a significant challenge. Managing even more routes by head- way would pose additional difficulties for operations. Collaborations with Stakeholders From the beginning of the MetroRapid service, Capital Metro collaborated closely with the City of Austin. Both entities were partners in planning and designing the MetroRapid routes, and key initial collaboration points included TSP implementation and dedicated bus-only lanes in the downtown area. Capital Metro and the City of Austin continue to collaborate on various speed and reliability improvement projects to work to advance transit operations generally and to improve the speed and reliability of the MetroRapid routes, specifically. One key collaboration relates to TSP. A city department, the City of Austin Transportation Department (ATD), owns and operates most of the traffic signals along the MetroRapid corri- dors. For the TSP system to work, the local stakeholdersâ signaling systems needed to integrate seamlessly with Capital Metroâs ITS systems. ATD and Capital Metro developed a joint TSP implementation plan and an interlocal agreement to formalize their collaboration and to make stakeholdersâ roles as clear as possible. In addition, both Capital Metro and ATD have at least one staff person dedicated solely to transit speed and reliability projects. The two agencies have adopted a joint approach to studying and improving transit speed and reliability. Although the MetroRapid routes are not the only
Case Examples 35Â Â routes investigated, several recent accomplishments highlight the productive nature of their partnership: â¢ Working together to assess the functionality of the TSP system and identify ways to continu- ally assess TSP performance. â¢ Painting the downtown dedicated only bus lanes red, as shown in FigureÂ 6. â¢ Implementing a contraflow only bus lane and dedicated signal phase to improve movement through a difficult intersection. Operations The MetroRapid routes operate on time points during weekends and during weekday early morning hours and late hours after 7:00Â p.m. Headway-based operations kick in on weekdays when the route goes to a 10-minute headway at 7:00Â a.m. Capital Metro uses several operational practices on the MetroRapid routes to maintain head- ways. In some cases, the practice is implemented by operators, but for the most part, dispatchers (i.e., bus control room personnel) give directions to operators. In 2020, Capital Metro devel- oped the Service Management Manual (known as the Playbook) that provides guidance to dispatchers, operators, street supervisors, and other key operations staff on what types of corrective actions to take when headway violations occur (Capital Metro 2020b). To help facilitate headway management, dispatchers use both the OrbCAD CAD/AVL system shown in FigureÂ 7 and Swiftly, as shown in FigureÂ 8, to monitor headways in real time. Bus operators can also see their headway status through the MDTs on MetroRapid buses. As shown in FigureÂ 9, the MDTs display a headway monitoring tool that provides the bus operator with the scheduled and actual headway for his or her leader and follower. The actual and sched- uled headways are displayed using a slash between them (e.g., 07/13 indicates a 7-minute actual headway and a 13-minute scheduled headway). Using these sources of real-time headway information, dispatchers and operators imple- ment one or more control strategies, based on the Service Management Manual, professional judgment, and current circumstances. Figure 6. Red only bus lane in Austin (Source: City of Austin Transportation Department 2020).
36 Intelligent Transportation Systems in Headway-Based Bus Service Figure 7. Example Capital Metro MetroRapid headway visualization (ladder style) provided by the OrbCAD CAD/AVL to MetroRapid dispatchers. Figure 8. Example of headway visualization (map style) provided by Swiftly and used by MetroRapid dispatchers (Source: Swiftly).
Case Examples 37Â Â Holding Holding may be initiated by operators or by dispatchers and is a corrective action for a bus that is beginning to catch up (or bunch) with its leader. Holding up to 3Â minutes may occur at any time point along the route where it is safe to do so. Operators are instructed to inform passengers that they will be holding for a few moments to allow other buses to get back on time. Passing Also called leap frogging, passing is used when a following bus has caught up with its leader. If the follower bus can do so safely, the follower can pass the lead bus, which is likely continu- ing to lose time from increased passenger demand. However, operators must send a canned message âCAUGHT LEADERâ through the CAD/AVL system so that dispatchers can acknowl- edge and address the situation, if needed. Short Turn A short turn is when a bus heading in one direction is taken out of service before reaching the terminus and is then placed back in service heading in the opposite direction. Short turns are used when buses are significantly behind schedule, and are only initiated by dispatchers. A dispatcher notifies the operator of the need to perform a short turn and provides instructions about where to do the short turn and where to resume service. Operators communicate with passengers about the short turn and will need to offload passengers and direct them to take the following bus. This method can make a big impact in headway management. However, it also has a big impact on passengers, so its use is rare. Stand-By Buses A stand-by bus is one that is available to be placed into revenue service when and where it is needed. Stand-by buses (called run-as-directed queue buses) are staged at strategic locations in the service area to enable them to respond to the most frequent operational issues. When there is a significant delay or mechanical breakdown, dispatchers can use stand-by buses, if available, to fill in for the delayed or stranded bus. Dispatchers initiate this action and provide direction to the stand-by operator when and where to begin and end service. Typically between one and two stand-by buses may be staged and available to operate on the MetroRapid routes. However, these buses may also be used to fill in for other incidents or problems on other non-MetroRapid routes, if needed. Figure 9. Bus operator MDT headway monitoring tool display (Source: Capital Metro internal documents).
38 Intelligent Transportation Systems in Headway-Based Bus Service Drop-Off Only A bus enters drop-off-only mode when it is running behind (i.e., is gapped or significantly behind schedule). The goal is to speed up the late bus by only alighting (not picking up) passen- gers. In this way, some stops might be able to be skipped if no one is getting off, and the dwell time at stops may be reduced by not boarding new passengers. This action is only initiated by the dispatcher, and dispatchers communicate with operators about how long to operate in drop-off only mode. The operators trigger a NEXT BUS PLEASE display on their head sign and work to only drop off passengers. In some cases, using the back doors only can help reduce the confusion of passengers waiting at stops expecting to be able to board. Like short turns, drop-off only is used sparingly and only if there are reasonably close buses following the drop-off-only bus with capacity to board the passengers that were expecting to get on the drop-off-only bus. Recovery The cycle times for the MetroRapid include recovery times at both ends of the route to allow for both operator breaks and for schedule recovery. Capital Metroâs rule of thumb is to schedule in recovery time that is 10% of the one-way trip time. This leads to scheduled recovery times that usually fall between 10 and 15Â minutes, depending on the time of day. Although recovery time can be a tool for correcting headway deviations, Capital Metro has found that there is a delicate balance to manage between headway performance and operator well-being and comfort. The MetroRapid routes are quite long and have one-way trip times that often exceed 100Â minutes. Operators need time to rest, relax, and use the restroom between trips. However, if an operatorâs bus is already gapped, using the full amount of recovery time will only exacerbate the headway gap. For 1Â week, Capital Metro performed an experiment to deter- mine how headway reliability would improve if all buses were actively dispatched at the correct headway from the termini, regardless of the resulting amount of layover. However, even with perfectly timed termini departures, the routes still struggled to maintain the desired headway. TSP Both MetroRapid routes are equipped with TSP at 132 (virtually all) intersections along the routes except for the intersections in the downtown area in which the routes operate in a dedi- cated bus lane shared by multiple bus routes. The TSP system is centralized, and the Capital Metro CAD/AVL system requests priority from the City of Austinâs traffic management center when buses are 60 or more seconds late and approaching a priority-eligible intersection. Buses that are granted priority receive a 7-second green extension. As designed, TSP is not directly based on real-time headways and instead uses a schedule adherence business rule to trigger a priority request. Updates Capital Metro consistently reviews the cycle times on the MetroRapid routes and adjusts as needed, often every schedule change, to respond to changing traffic and ridership patterns. There are typically three schedule changes per year, in January, June, and August. To the extent possible, Capital Metro also makes adjustments to the number of assigned buses, as needed, to accommodate periods when cycle times are longer and require more buses to maintain the desired headway. Performance Monitoring Capital Metro tracks performance on the MetroRapid lines, including headway adherence during high-frequency periods and schedule adherence during lower-frequency periods. When calculating headway adherence, Capital Metro measures headway events at time points, which are also MetroRapid stations. In other words, when a MetroRapid bus arrives at a time point, a headway event is captured, and the event is categorized as early, on-time, or late (i.e., gapped).
Case Examples 39Â Â Early events are not counted against the routeâs performance, and end-of-line stations are excluded from the headway adherence calculation. An event is categorized as late if the actual headway (i.e., the time that passed since the previous bus on the same route and direction) exceeds the on-time allowance: 50% of the scheduled headway or 5Â minutes, whichever is less. For example, if the bus has a scheduled 8-minute headway, then the on-time allowance is 4Â minutes (50% of the scheduled headway). A bus that arrives after 12Â minutes would be con- sidered late (i.e., 8Â minutes of scheduled headway plus 4Â minutes of on-time allowance). For times when buses have headways longer than 10Â minutes, then the default 5-minute on-time allowance is used because 5Â minutes is less than 50% of the headway value. For example, if the bus has a scheduled 15-minute headway, then the on-time allowance is 5Â minutes. A bus that arrives after 20Â minutes (15Â minutes of scheduled headway plus 5Â minutes of on-time allowance) would be considered late. MetroRapid headway adherence is measured regularly and is used for internal performance monitoring and board- and public-facing reports, including an online dashboard, as shown in FigureÂ 10. Internally, a small group of operations stakeholders receive a headway performance report three times daily. Public performance reports are updated monthly. According to the online dashboard, the MetroRapid routes have remained consistently at or above 84% on-time over the 12Â months from SeptemberÂ 2019 through September 2020. Capital Metro is also exploring other performance measures for the MetroRapid routes based on the concern that the 50% or 5-minute on-time allowance may not fully reflect operational realities and the customer service challenges that may result from uneven headways. Also, the current percentage-based approach is not sensitive to the changes in the magnitude of head- way gaps (small gaps of 5Â minutes are counted the same as larger gaps of up to any possible value). One approach currently being explored is calculating a median absolute headway devia- tion value for the routes at different locations and at different times of day. A median absolute headway deviation is sensitive to both the frequency and magnitude of headway deviations. However, this method is still in development and testing and has not yet been fully adopted for performance monitoring. Personnel Capital Metro has made some recent changes to how MetroRapid routes are monitored from its radio room (i.e., control center). In 2019, Capital Metro began having dispatchers dedi- cated to monitoring and controlling service on the MetroRapid routes. Depending on the time of day and contingent on staff availability, Capital Metro has one dispatcher assigned to each Figure 10. MetroRapid on-time performance September 2019 through September 2020 (Capital Metro 2020c).
40 Intelligent Transportation Systems in Headway-Based Bus Service of the two MetroRapid routes. In some cases, the dispatchers may assist one another or other dispatchers working incidents on other bus routes. In addition, the radio room supervisor is also tasked with monitoring the MetroRapid routes and working with dispatchers to help manage headways and handle other operational issues. As previously mentioned, dispatchers have been trained on the Service Management Manual and use this as a guide to what corrective actions should be taken by dispatchers under different headway and service scenarios. Capital Metro has also begun to more actively incorporate street supervisors in monitor- ing and controlling MetroRapid service from the field. Street supervisors have laptops in their vehicles that can access the same screens as dispatchers. To the extent possible, street supervisors and dispatchers coordinate their efforts in managing headways. Bus operators also play an important part in managing headways on the MetroRapid. Because of their MDTs, bus operators can see the actual live headways compared to the scheduled head- way. Operators are instructed, to the extent possible, to attempt to maintain the correct headway between their leader and follower through slight modifications to speed. However, a dispatcher must pre-authorize significant reductions in speed or holding. In addition, MetroRapid operators must be familiar with the unique characteristics of the MetroRapid service. For example, both MetroRapid routes travel through intersections equipped with queue jumps and even a special bus-only left-turn phase. Also, passengers are allowed to board at all doors, and rear doors are equipped with fare validators to validate mobile passes. Above all, operators must be aware of the headway-based operation of the MetroRapid routes and must know how to successfully and safely adjust operating speeds to maintain spacing. Summary Capital Metro operates HBS on two BRT routes under the MetroRapid service name: Routes 801 and 803. These routes have several features to reduce travel time variability and delay along the route. However, significant portions of the routes operate in mixed traffic. Managing head- ways on the MetroRapid routes is a consistent and ongoing effort that needs constant monitor- ing and action, and maintaining desired spacing continues to be a challenge. In addition to infrastructure-based strategies (e.g., bus-only lanes or re-engineering of certain problematic intersections or corridors), Capital Metro focuses much of its attention on daily operations and control strategies initiated by dispatchers (e.g., holding and drop-off only). Challenges Capital Metro faces several challenges related to managing headways on the MetroRapid routes. First, operating in mixed traffic (even with the downtown dedicated transit lanes) can result in significant delays from traffic congestion, intersections, construction, and other imped- iments to free-flow travel. Although downtown congestion is relatively predictable, congestion on the distal parts of the routes can be highly variable. The corridors the MetroRapid routes use run parallel to the regionâs main north-south routes, including MoPac Expressway and Interstate Highway 35. When incidents occur on these north-south routes, traffic often spills over onto the MetroRapid corridors and causes further service challenges. Traffic congestion and incidents not only create travel time variations that may cause headway violations but also create significant fluctuations in the routesâ cycle times. When scheduled recovery times are not enough to absorb cycle time variability, gapping automatically occurs because the cycle time would be too long for the number of vehicles on the route to provide the desired headway.
Case Examples 41Â Â A second challenge is fluctuations in passenger demand. The MetroRapid routes both pass by significant trip generators and points of interest, including the University of Texas at Austin. For that reason, several different peaks in ridership demand occur throughout the day in addition to the typical a.m. and p.m. peaks resulting from work trips. Another challenge is capacity. Prior to the COVID-19 pandemic, demand on the MetroRapid routes often resulted in buses being filled to capacity. As buses fill up, dwell times can increase because it takes longer for passengers to board and alight. Also, with this heavy ridership, imple- menting a control strategy that has a passenger impact can negatively affect a large number of passengers either on the bus or waiting for the bus. This high ridership makes major, more effec- tive control strategies (e.g., short turns or long holds) less appropriate. Another challenge is the configuration of the TSP system. As previously discussed, the TSP system requests priority when a bus is 60Â seconds or more behind schedule, not considering the busâs current headway status. If buses are late according to schedule, which they often are, both bunched and gapped buses are requesting priority, and giving a bunched bus priority is not desirable. Or, if a bus is on-time but gapped, that bus will not request priority even though reducing that busâs intersection delay would be a helpful tool to reduce the headway gap. Capital Metro is currently investigating the possibility of changing the TSP system configuration to trigger priority requests based on headway status instead of schedule adherence status. Lastly, challenges are also associated with personnel. Those challenges manifest themselves in many different ways. For example, most operators, dispatchers, and supervision staff are adept at schedule-based operation and management of routes. However, getting all operators, dispatchers, and supervisors to fully understand and embrace headway-based operations is a challenge. There is often little time for specialized training, and so many of the standard operat- ing procedures and rules are built around schedule-based operations. Keeping all levels of staff engaged in headway management is critical for success but can be quite difficult given the daily challenges facing transit operations. As all transit agencies have done, Capital Metro has made numerous changes in response to the ongoing COVID-19 pandemic. In MarchÂ 2020, when the pandemic was first making significant changes to daily life in the United States, Capital Metro reduced service on the MetroRapid routes (and most other routes) to a Sunday schedule, which meant that headway- based operations ceased, and the routes were operated according to schedules. In AugustÂ 2020, Capital Metro returned to its regular weekday and Saturday schedules, re-implementing headway-based operations during weekdays. In response to significantly reduced traffic and ridership, Capital Metro adjusted down the cycle times. Capital Metro also instituted a 50% capacity cap on fixed-route service and requires operators to notify dispatch if their bus reaches a 50% load so a stand-by bus can be sent to provide more space for additional riders. Notable Practices The MetroRapid routes have been in operation for about 6Â years, and challenges with main- taining headways persist. However, despite these challenges, Capital Metro does have some notable practices that both support the routesâ headway-based operations and also seek to con- tinually advance headway reliability beyond what it is today: â¢ Implementation of the Service Management Manual. The Service Management Manual is a single go-to resource that provides dispatchers, supervisors, and operators with a consistent terminology and set of techniques for headway management. Although the manual is consid- ered a working document, it contains key information that helps to support headway-based operations.
42 Intelligent Transportation Systems in Headway-Based Bus Service â¢ Coordination with the City of Austin. When the MetroRapid routes were first imple- mented, the City of Austin and Capital Metro coordinated heavily on treatments to help the routesâ speed and reliability, including dedicated bus lanes downtown, queue jumps at selected intersections, and TSP. Although coordination has not always been easy, the coor- dination continues today through joint efforts, including creating a speed and reliability program at both agencies. â¢ Creation of a joint speed and reliability program. Capital Metro and the City of Austin collaborated to create a joint transit speed and reliability program. Both agencies created a position dedicated to the program, and these two individuals work together to develop a strategic plan to prioritize investments in problematic corridors (not limited to MetroRapid) to help improve transit operations. â¢ Dispatchersâ use of Swiftly screens in the radio room. The Capital Metro dispatchers who are assigned to the MetroRapid routes use not only their traditional CAD/AVL screens for headway and incident management, but also Swiftlyâs live operations map. Buses update their positions to Swiftly every 10 seconds, giving dispatchers an almost real-time view of the status of MetroRapid buses. The Swiftly map can color-code buses based on headway status and provides a user-friendly and familiar base map and interface for dispatchers to work with. Dispatchers use the CAD/AVL system to actually make adjustments to buses, handle inci- dents, and record their activities. Lessons Learned Capital Metroâs experience with the MetroRapid routes has produced the following insights, which may influence future projects and be valuable to other agencies: â¢ Maintaining headways in mixed traffic can be challenging and needs consistent and pro- active management. Operating in mixed traffic makes maintaining headways difficult. Small incidents can easily cascade into significant bunching or gapping. The MetroRapid routes need a high level of engagement from operators, dispatchers, and street supervisors, making real-time adjustments to minimize headway deviations. In addition, planning and sched- uling staff need to consistently evaluate running times, look for corridor bottlenecks, and identify other sources of travel time variability. â¢ Headway measurement is critical to understanding performance and assessing the effectiveness of initiatives and projects. Without a solid and trusted headway performance measure, it is impossible to understand, first, how well buses are maintaining headways and, second, whether programs, policies, or other interventions help improve headway reliability. There are pros and cons to any performance measure, but measures that help identify both the frequency and severity of headway deviations may provide a more robust understanding of actual headway conditions. â¢ TSP needs to be consistently assessed and evaluated. The functionality and effectiveness of TSP systems cannot be taken for granted. In fact, Capital Metro recently assessed its TSP systemâs functionality and found several issues that needed addressing to bring the system back to desired functionality. In addition, the effectiveness of TSP for HBS may be limited if both gapped and bunched buses are asking for TSP with the same frequency. Finding the optimal set of TSP business rules and parameters takes a concerted effort, and a customized approach to business rules for HBS may be most beneficial. â¢ ITS systems may use different algorithms for calculating headways. Because Capital Metro has two different systems that provide estimated headways (i.e., Swiftly and OrbCAD), Capital Metro has found some circumstances when live headway calculations may not be in agreement, causing confusion for drivers and dispatchers and leading to a potential lack of trust in either system. It is important to understand the differences between different ITS systems and to communicate these differences to system users so system confidence is not reduced.
Case Examples 43Â Â â¢ Staff coordination is critical. Because there are so many different people involved in successfully operating the MetroRapid routes, continual coordination at all levels is critical to success. Bus operators, street supervisors, dispatchers, schedulers, planners, engineers, ITS professionals, and others all need to be working together. Although coordination is needed even for schedule-based service, when transit agencies operate both schedule-based service and HBS, the delineation between schedule- and headway-based operations and procedures needs to be clear, and all staff need to be aligned to ensure success. Los Angeles County Metropolitan Transportation Authority Introduction Los Angeles County Metropolitan Transportation Authority (LA Metro) is the transit agency for Los Angeles County, California. Its service area includes the city of Los Angeles as well as many surrounding cities. TableÂ 17 summarizes the agencyâs modes and operating statistics. LA Metro is organized as a public agency with a board of directors including representatives from Los Angeles County, the City of Los Angeles, and other cities in the service area. Most transit services (including all BRT, the focus of this case example) are directly operated. LA Metro was selected as a case example because it represents a large city with high rider- ship. In addition, LA Metro reported the shortest headways and highest benefit ratings of any surveyed agency. Operating Context Currently, LA Metro operates one route by headway: the G Line (formerly known as the Orange Line). The G Line is a BRT route in the San Fernando Valley that runs from North Hollywood to Chatsworth. The route has dedicated right of way (ROW) along its entire length and has 17 stations. The San Fernando Valley is generally suburban but has significant demand generators. For instance, the North Hollywood terminus connects to the B Line (formerly the Red Line) subway, and the Chatsworth terminus connects to Metrolink commuter rail. The G Line is an at-grade busway and is equipped with TSP at intersections with cross streets. Buses are detected by means of loop detectors in the pavement as they approach the inter- sections. The stations have ticket machines and smartcard readers, which allow the route to use off-board fare collection and all-door boarding policies. The G Line is typically among the top four or five routes by ridership in LA Metroâs system and runs at a 4- to 5-minute headway. The route is served by a dedicated fleet of articulated buses that have separate branding from local buses. Mode Unlinked Passenger Trips Vehicles Operated at Maximum Service BRT 7,168,515 31 Bus 273,625,420 1,885 Heavy rail 43,752,286 68 Light rail 66,387,207 196 Vanpool 3,428,229 1,278 Source: National Transit Database 2018. Table 17. LA Metro key annual operating statistics by mode.
44 Intelligent Transportation Systems in Headway-Based Bus Service System Development The G Line was a former railroad ROW that LA Metro purchased in 1991 to develop into a transit corridor. Early planning considered both rail and bus options. After Proposition A, a local ballot measure, blocked funding for rail in 1998, LA Metro decided to develop the corri- dor as a BRT line. The first phase of the G Line opened in 2005, and an extension to Chatsworth opened in 2012. The first phase had a capital cost of $304.6Â million in 2004 dollars, of which $8.2Â million was for systems and equipment (Flynn etÂ al. 2011). The G Line has always been operated by headway and was designed with several features that make headway-based operation easier: dedicated ROW, TSP, a limited number of stations, off-board fare collection, and all-door boarding. In terms of ITS, LA Metro has AVL, CAD, PIS, a smartphone app, and TSP. Many of these are common to all bus services. All-door APCs, TSP, and station amenities (electronic arrival signs, ticket machines, and park and rides) are distinctive features of the G Line. The G Line is also the only route on its corridor. There are connections with other bus routes and rail lines, but none of them share stations or route segments with the G Line. LA Metro has discussed operating other bus routes by headway. One obstacle to implemen- tation is uncertainty about how to provide trip planning and arrival estimates to passengers in a mixed headway- and schedule-based system. If all routes were operated by headway, then LA Metro could convert the entire PIS to headway estimates. However, LA Metroâs bus network is large, and staggered implementation would be easier to manage. The next routes likely to see HBS are the J Line (formerly known as the Silver Line) and Wilshire service (Routes 20 and 720). The J Line is another BRT line with many similarities to the G Line: semi-exclusive ROW, a limited number of stations, some off-board fare collection, and all-door boarding. The J Line has some complicating factors like street running in downtown, branches, and varying demand. The Wilshire service already has 3-minute headways in mixed traffic on a busy arterial street. As a result, Wilshire is a more complicated route and has numerous external factors that can cause bus bunching. Collaborations with Stakeholders One key collaboration relates to TSP. A city department, the Los Angeles Department of Transportation, owns and operates the traffic signals along the G Line. The city constructs the loop detectors used to detect buses, while LA Metro pays for the maintenance of these sensors because they are on their transit way and provide TSP to their buses. The City of Los Angeles performs the maintenance because they own the traffic signals and employ the traffic signal technicians. LA Metroâs ITS sends and receives data with city, county, state department of transportation, and third-party data providers. From a data perspective, information is shared with various third-party data providers. This collaboration is systemwide and is not specific to HBS. The San Fernando Valley (where the G Line is located) is fairly sophisticated in terms of stake- holder engagement. There was significant community discussion before the G Line was built about which mode should be selected and what the service should look like. Since the line opened, service councils and cities monitor its operation and have a monthly update meeting with LA Metro to discuss issues. These meetings cover operational issues, cosmetics, and other topics. Operations LA Metro uses several operational practices on the G Line to maintain headways. Holding Holding is practiced by the bus operators, who try to avoid departing too early or getting too close to the bus in front.
Case Examples 45Â Â Passing When one bus starts to slow down (generally due to a high passenger load), the buses behind are allowed to pass. Recovery The cycle times for the G Line include generous recovery times at both ends of the route. These recovery times are usually enough to allow buses to start their next trip on time, prevent- ing disturbances from propagating from one direction to the other. TSP G Line buses can receive a 10-second green extension at signalized intersections. While TSP is not directly based on real-time headways, there is a lockout period after successful TSP requests that is based on the scheduled headway. This rule means that a second bus arriving in quick succession would not receive priority, indirectly helping to break up bus bunches. Updates LA Metro reviews the cycle times on the route every 6 months and makes adjustments if needed. The G Line has been in operation since 2005 and is relatively stable. The route is not affected by traffic because it operates entirely on exclusive ROW and has had the same 4- to 5-minute headway for a while. Performance Monitoring LA Metro tracks various performance measures for the G Line, including headway adher- ence, headway variability, route travel times, and passenger satisfaction. Passenger satisfaction is captured through an annual passenger survey by the Communications Department and by tracking complaints. In addition to these measures, schedule adherence (defined as 1Â minute early to 5Â minutes late) and the number of accidents are tracked for all bus routes. Personnel LA Metro has dedicated dispatchers for the G Line Monday through Friday, while dispatchers may be shared between the G Line and other bus routes on weekends. LA Metroâs dispatchers are generally distributed by region, so two or three controllers are assigned to the San Fernando Valley. Dispatchers generally monitor video feeds at stations and exchange messages with bus operators. There are no specific dispatching procedures for HBS. The G Line has some unique systems, but otherwise the same procedures are used for all bus routes. Dispatchers do not rotate, so the same people are always assigned to the G Line/San Fernando Valley. For bus operators, signals, signage, and passenger loading are different on the G Line compared to other bus routes. Operators may drive several different routes and rotate from time to time, so they have to be aware of the differences on the G Line. For several years, G Line buses had a 15-mph speed restriction at intersections imposed because of concerns about high crash rates. Many crashes were caused by other road users not watching for buses as they crossed the exclu- sive ROW. The speed restriction has now been lifted. In general, bus operators like the G Line because they do not have to collect fares and have fewer interactions with passengers and traffic. Summary LA Metro operates HBS on one BRT route, the G Line. This route has many features that limit variability in running time and dwell time, including exclusive ROW, TSP, off-board fare col- lection, and all-door boarding. These features, combined with generous recovery times at both
46 Intelligent Transportation Systems in Headway-Based Bus Service ends, have generally been enough to stabilize operations on the route. Additional real-time oper- ational strategies include holding and passing, and bus operators typically make these decisions. Challenges One challenge is fluctuations in demand. The G Line passes by three colleges, and student ridership produces several peaks throughout the day in addition to the normal a.m. and p.m. peaks. Student demand is closely tied to class schedules and is different every quarter/semester, which makes it difficult to plan for. LA Metro has also observed that student demand is highest at the beginning of every semester and tends to decline as the semester goes on. Another challenge is capacity. The G Line is close to capacity, but the constraints of TSP make it challenging to run headways shorter than 4 minutes. LA Metro is exploring the idea of bus platoons, where two buses would run back to back and share station platforms and TSP calls, as a way to provide additional capacity. Another proposal to address the capacity issue is to convert the G Line to light rail. As all transit agencies have done, LA Metro has made numerous changes in response to the ongoing COVID-19 pandemic. As of July 2020, LA Metro had made two service changes systemwide with one more planned for August. LA Metro has been monitoring ridership data on a weekly basis and deciding where to add or modify service. Previously, service updates were made every 6 months. The G Line is currently operating a Sunday schedule with 10-minute headways all day. Ridership is down 70% systemwide, but service levels have been maintained somewhat higher to reduce passenger load and allow for social distancing. LA Metro is talking about a target of 75% passenger load for the August schedule update to balance social distancing needs with resource (bus and operator) constraints. All passengers are now required to wear masks. This rule is not really enforced due to operator concerns, but LA Metro estimates that 90% of passen- gers are wearing a mask. Still, LA Metro has received many passenger complaints about crowded buses and the risk of COVID exposure. Notable Practices The G Line has been in operation for nearly 15Â years. LA Metro reports that headway-based operation is performing well and that the route is relatively stable at this point. Key contributors to its success are â¢ Features to reduce running time variability. The G Lineâs exclusive ROW eliminates traffic impacts, and TSP reduces the travel time variability caused by signals. Additionally, the route has a limited number of high-amenity stations that are unlikely to be skipped. Stop skipping can be a source of travel time variability on routes with a high stop density because not every stop is served on every trip. â¢ Features to reduce dwell time variability. Off-board fare collection reduces the time it takes each passenger to board. All-door boarding allows multiple passengers to board simultane- ously, reducing the total boarding time. All-door boarding is especially useful with articulated buses, which are used on the G Line. â¢ Recovery time. LA Metro provides significant recovery time at both ends of the route. This practice is especially valuable in HBS because it allows buses to begin each trip at regular headways and prevents problems from propagating from one direction to the other. Lessons Learned LA Metroâs experience with the G Line has produced the following insights, which may influ- ence future projects and be valuable to other agencies:
Case Examples 47Â Â â¢ All-door boarding is popular. Both passengers and bus operators like off-board fare collection and all-door boarding. While installing a ticket machine at every stop would be cost prohibitive, LA Metro can put a smartcard validator on every bus door. That would allow all- door boarding for smartcard users and might encourage further smartcard adoption. â¢ Dedicated bus lanes are effective. The exclusive ROW on the G Line is effective and helps maintain headway-based operation. Passengers also perceive dedicated lanes as a higher- quality service. For these reasons, LA Metro is likely to build more dedicated bus lanes in the future. â¢ TSP works but could be improved. Downtime has been an issue. The TSP system relies on loop detectors to detect buses, and these sensors sometimes break down. The city handles maintenance but has thousands of intersections and sensors to take care of and sometimes takes a while to respond to an issue. Meanwhile, TSP is unavailable at the affected intersec- tion and direction until the sensor is repaired. The city is also bound by new Americans with Disabilities Act requirements for longer pedestrian crossing times at any new or upgraded intersection. This rule is important for pedestrians but reduces flexibility in the signal cycle and constrains the use of TSP. King County Metro Transit Department Introduction The King County Metro Transit Department (King County Metro) is the transit agency for King County, Washington, which includes the City of Seattle. TableÂ 18 summarizes the agencyâs modes and operating statistics. King County Metro is organized as a public agency within the King County organizational umbrella, which is managed by the King County Executive and County Council. Most transit services (including all BRT, the focus of this case example) are directly operated by King County Metro. King County Metro does not currently operate HBS although it has experimented with it in the past. King County Metro is currently involved in a pre-scoping project, in which it is assessing the potential of a system of transit management strategies, which include HBS, among others. The system is referred to as advanced service management (ASM). King County was selected as a case example because it represents a large city with high ridership. Background King County Metro does not operate HBS. However, King County Metro is currently amid a ramp-up for ASM. ASM could include HBS, seat sliding, hot seating, and other more advanced transit management strategies. The ASM scoping has been going on for about 1Â year. Mode Unlinked Passenger Trips Vehicles Operated at Maximum Service Demand response 888,312 304 Demand responseâtaxi 143,747 71 Ferryboat 664,365 2 Bus 104,261,625 1,015 Streetcar rail 1,685,668 10 Trolleybus 17,950,742 140 Vanpool 3,464,738 1,608 Source: National Transit Database 2018. Table 18. King County Metro key annual operating statistics by mode.
48 Intelligent Transportation Systems in Headway-Based Bus Service King County Metro first launched its BRT brand, called RapidRide, in 2010. At that time, King County Metro used HBS. As the number of RapidRide lines increased, HBS was discon- tinued due to resource constraints, technology issues, and complexity of operations. About 1Â year ago, staff was asked by King County Metro leadership to revisit the use of HBS. In response, a workgroup was formed to focus on the issues. King County Metro ini- tially performed an industry scan to obtain a general overview of how HBS had evolved since it was first implemented at King County Metro. Realizing the benefit of learning from other agencies that had successfully implemented HBS, King County Metro decided to conduct site visits. King County Metro staff identified multiple transit agencies with successful HBS implementations and began to visit them. However, this work was paused due to COVID-19 and other issues. Only recently has the effort gained momentum again. Some questions that King County Metroâs pre-scoping work helped answer are as follows: â¢ What next steps are needed to advance ASM implementation? â¢ What are the internal agency constraints? â¢ What investments (including staff, technology, and facilities) are needed to implement ASM? One significant constraint is that ASM touches all aspects of King County Metroâs organiza- tion including elements of bus operations, technology, capital delivery, scheduling, and other areas. Therefore, King County Metro took time to identify where the program should reside administratively. Given the enterprise implications of the program, ASM will be housed in the General Managerâs Office during this initial phase. Implementation King County Metro is in the early stages of transitioning from pre-scoping work to formal project initiation. While the direction of the project could change, King County Metro shared initial thoughts on the direction of the project at this stage. King County Metro believes that when ASM is implemented, it is likely to be implemented on RapidRide routes first. These routes have traditionally been where King County Metro first rolls out new technologies, and high-frequency service makes them well suited for this type of opera- tions. King County Metro also realizes that ASM makes sense on other routes with high-frequency service such as trolley bus routes, some of which will become RapidRide routes in the future. King County Metro is interested in conducting a pilot to inform system requirements of a larger-scale implementation. For the pilot, King County Metro has considered using the soft- ware system it has in place, which would require addressing the issues it has experienced in the past. King County Metro has also looked at other solutions that use in-vehicle tablets or wayside real-time information signs. For the pilot, these solutions could be implemented on a specific route, or be implemented with a subset of operators. Implementation with a subset of operators would provide for a control group, which would be analytically beneficial. Initiating a pilot will depend on the scope of the project and various other approvals. Pilot Evaluation King County Metroâs pre-scoping work has identified the following metrics as potential measures for evaluating the pilot: â¢ Improving reliability. â¢ Improving resilience. â¢ Improving customer experience regarding travel time.
Case Examples 49Â Â â¢ Reducing crowding and pass-ups. â¢ Reducing peak-period bus needs. â¢ Reducing layover needs in areas with capacity constraints. â¢ Improving operator satisfaction. â¢ Developing sustainable strategies that are deployed appropriately and can be scaled on route- specific needs. â¢ Improving the efficiency of service. Training and Staffing King County Metro has just under 3,000 operators and special training will be needed. Realiz- ing that ASM will be on a subset of routes, not all operators will need to be trained. King County Metro training will be specific to those that are asked to use it, with training depending on work assignments. King County Metro dispatchers have a large number of responsibilities, so addition of respon- sibilities will require additional dispatchers. King County Metro will look at this more closely during the pilot. Operator Autonomy King County Metro has identified two levels of HBS based on pre-scoping work, with the second building upon the first: â¢ Level 1. Operators have information on their headway relative to their leader and follower, and they have a playbook of simple strategies to maintain headways as well as possible given those strategies. This level is simpler because it does not require intervention from dispatchers, but less effective in resolving the larger headway issues. â¢ Level 2. This builds on the first level and adds active intervention by dispatchers. Dispatchers have a holistic picture of operations and can direct operators to utilize more advanced strategies to resolve headway issues. This level is more complex but can address larger headway issues. King County Metro realizes that there are many other factors at play, such as the resources allocated and what types of technology and infrastructure are in place. Stakeholder Involvement To date, this pre-scoping effort has been largely internal and workgroup focused. King County Metro has involved King County IT, which is the provider of King County information technol- ogy services. The City of Seattle has shown an interest in the project. Before COVID-19, layover space in downtown Seattle was at a premium. More efficient uses of buses that lower layover time and increase the proportion of time spent on revenue service could reduce layover space on city streets. Looking ahead, King County Metro will involve operators and the operatorsâ union as this project could change some elements of their work. Barriers King County Metro has identified the following barriers to ASM implementation: â¢ Administratively, where should the program reside within King County Metro due to the complexity of the project?
50 Intelligent Transportation Systems in Headway-Based Bus Service â¢ The transit control center is currently housing the maximum number of dispatchers it can house. To make implementation a reality, King County Metro would need to increase the size of the Transit Control Center. â¢ Staff size and staff mix are also something King County Metro would have to address prior to implementation. â¢ Technology has been an issue with HBS. King County Metro would like to use its current system if possible because transitioning to an entirely new system is expensive and time- consuming, but the experience of other transit agencies with the same technology systems has indicated that this might not be successful. Other technology needs due to old technology systems adds complexity to this project. Summary of Case Examples The four case examples provide insight into different motivations for using headway-based operation and the factors that are key to its success. TableÂ 19 summarizes the challenges, notable practices, and lessons learned from each case example. Transit Agency Challenges Notable Practices Lessons Learned TheBus â¢ Driver compliance and attentiveness to headway guidance â¢ Routes with multiple service patterns (e.g., limited stop) â¢ Route 8 buses used as stage vehicles on other routes â¢ Headway target adapts to current cycle time and fleet allocation â¢ Dynamic adjustment valuable during COVID- â¢ Driver buy-in is key â¢ Drivers new to headway- based operation benefit from additional dispatcher and supervisor attention 19 LA Metro â¢ Demand variability â¢ Nearing capacity and technical constraints on TSP below current headway â¢ During COVID-19, trade-off between resources and low load factors for social distancing â¢ Low travel time variability due to exclusive ROW and TSP â¢ Low dwell time variability due to all-door boarding and off-board fare collection â¢ Long layovers provide recovery time â¢ Reliability-enhancing features are also popular with passengers â¢ TSP valuable but has some issues with maintenance and constraints on signal timing Capital Metro â¢ High variability in traffic and passenger demand â¢ Buses reaching capacity â¢ TSP still tied to schedule â¢ Training personnel for headway-based operation â¢ Service management manual â¢ Coordination with the City of Austin; joint speed and reliability program â¢ Dispatcher use of Swiftly screens to supplement CAD/AVL â¢ Mixed traffic segments require consistent and proactive management â¢ Headway performance measurement is critical â¢ TSP requires consistent monitoring â¢ Different ITS may use different methods for calculating headway â¢ Staff coordination is critical King County Metro â¢ Transit Control Center at capacity â¢ Dispatcher priorities; incidents come first â¢ Limited by functionality of current ITS â¢ Planning staged implementation to assess benefits and refine strategies â¢ Plan to give drivers information and some discretion on how to act â¢ Previously had HBS; stopped due to resource constraints â¢ Organizational buy-in is important and touches many different areas Table 19. Summary of case examples.