Cover Image

Not for Sale

View/Hide Left Panel
Click for next page ( 128

The National Academies of Sciences, Engineering, and Medicine
500 Fifth St. N.W. | Washington, D.C. 20001

Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement

Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 127
Congestion Pricing Case Studies 133 7. Washington State Department of Transportation SR 167 HOT Lanes The Washington State Department of Transportation (WSDOT) operates a total of 764 cen- terline miles of Interstate highway out of a statewide network of 174,430 miles of roads. There are only two toll facilities in Washington State: the Tacoma Narrows Bridge and the SR 167 HOT lanes, which is the subject of this case study. Toll revenues represented approximately 4 percent of WSDOT total revenues of $3.2 billion in 2007, nearly all of which was generated by the Tacoma Narrows Bridge.4 The bridge's tolls are being used to repay revenue bonds used to finance its construction, a mechanism used many times in the past by Washington State. WSDOT plans to introduce congestion pricing on the SR-520 Evergreen Point Floating Bridge with the support of a $154.5 million UPA grant from USDOT and is also exploring the use of congestion pricing on other major highway facilities in the Puget Sound region. In 2003 the Washington State Transportation Commission directed WSDOT to assess the possible conversion of HOV facilities in the state to HOT-lane operation. WSDOT identified the SR 167 as a suitable pilot project for a HOV-to-HOT conversion because of congested con- ditions in the general-purpose lanes and unused capacity in the HOV lane. Governor Christine Gregoire signed State Highway Bill 1179 which called for a 4-year conversion demonstration. The bill also identified performance data and supporting information to be included in an annual report to the State Legislature documenting the performance of the SR 167 HOT lanes. The bill states that The department shall monitor the state route 167 high-occupancy toll lane pilot project and shall annually report to the transportation commission and the legislature on operations and findings. At a minimum, the department shall provide facility use data and review the impacts on: a. Freeway efficiency and safety; b. Effectiveness for transit; c. Person and vehicle movements by mode; d. Ability to finance improvements and transportation services through tolls; and e. The impacts on all highway users. The department shall analyze aggregate use data and conduct, as needed, separate surveys to assess usage of the facility in relation to geographic, socioeconomic, and demographic information within the corridor in order to ascertain actual and perceived questions of equitable use of the facility. The 4-year demonstration will conclude on May 3, 2012, when the Washington State Legisla- ture will have to act to make the authorization permanent. 7.1. Overview of WSDOT's Congestion Pricing Program The SR 167 HOT lanes opened to service on May 3, 2008. A single HOT lane runs in each direc- tion of SR 167 between Renton and Auburn in southern Kings County. The northbound lane, approximately 11 miles long, begins at 15th Street SW in Auburn and ends at I-405 in Renton, while the southbound lane, 9 miles long, begins at I-405 and ends at 15th Street NW. The two general-purpose lanes in each direction remain toll free and open to all vehicles. Carpools of two or more people, vanpools, transit vehicles, and motorcycles may use the HOT lanes at no cost, and they may enter the lanes without a transponder. Single-occupant passenger vehicles may pay to use the HOT lanes from 5 A.M. to 7 P.M. daily and must be equipped with a WSDOT "Good To Go!" electronic toll collection (ETC) tag to use the lanes. The SR 167 features dynamic tolling with 4 AASHTO Center for Excellence in Project Finance

OCR for page 127
134 Evaluation and Performance Measurement of Congestion Pricing Projects rates adjusted every 5 minutes based on real-time congestion levels to ensure that traffic in the HOT lane always flows smoothly and that buses and carpools enjoy the same trip as they did prior to the conversion to HOT operation. The HOT lane is separated from the general-purpose lanes by a solid double white line, which is illegal to cross. Access in and out of the HOT lane is restricted to access zones identified by a dashed line. There are six northbound and four south- bound access zones. Prior to the conversion, motorists using the SR 167 HOV had continuous access to the lanes and could enter or exit the lanes at any location. 7.2. What Is Monitored? The full spectrum of WSDOT's performance monitoring activities is provided in the accom- panying Facility Performance Monitoring Summary Matrix for the SR 167 HOT Lanes. The matrix is a comprehensive record of all current, known metrics used to monitor performance on the facility, organized by evaluation category. Provided in the matrix for each metric used are frequency of collection, purpose, a simple indication of importance, and particular characteri- zations of the metric that relate back to agency/facility goals or applications. An expanded ver- sion of the matrix providing sources of information and other notes is included in the Final Report for NCHRP 08-75 which is available on line. The matrix is intended to be a visual overview of WSDOT's complete monitoring effort, easily comparable to other HOT-lane facil- ities with similar matrix summaries. A more qualitative discussion of how these metrics are applied in practice and which ones are the most significant is provided below. Not all metrics noted in the matrix are discussed here. WSDOT collects a comprehensive set of monitoring parameters for the SR 167 HOT-lane facility. These include automated data on traffic volumes and speeds in both the managed and general-purpose lanes collected by loop detectors. WSDOT tracks volume and speed data in multiple timeframes and compares conditions in the general-purpose and managed lanes, as well as the peak and non-peak direction of traffic. In addition to the data it collects from loop detec- tors in the corridor, WSDOT receives comprehensive data on toll transactions reported in a stan- dard format by its toll operator. This includes information on the number of toll transactions, toll rates, and revenue, which are reported by time-of-day and direction of travel. This informa- tion can be aggregated or broken down into intervals as small as 5 minutes. The SR 167 HOT lane enabling authorization requires that average travel speeds during peak hours (7:008:00 A.M. and 4:005:00 P.M.) of at least 45 mph are maintained at least 90 percent of the time. Monitoring data from the first year of operation demonstrates that the facility exceeds this requirement, meeting the speed threshold 99.2 percent of the time. WSDOT also uses end-to-end travel times as a measure of reliability. For example, it measured that the north- bound peak-hour (7:008:00 A.M.) travel time in the HOT lane was 11 minutes on average. Its data indicates that the 95th percentile travel time was also 11 minutes. This means that motorists traveling northbound during the peak hour will experience an 11-minute travel time 95 percent of the time. The southbound lane demonstrated similar travel reliability, with an average travel time of 8 minutes, for which the 95th percentile travel time is also 8 minutes. WSDOT makes a compelling case for the reliability of the HOT lane by comparing travel met- rics to those on the general-purpose lanes, where the average weekday northbound peak-hour travel time was 19 minutes, with a 95th percentile travel time of 26 minutes, and a southbound peak-hour travel time of 12 minutes, with a 95th percentile travel time of 19 minutes. WSDOT also tracks travel-time savings between the managed and general-purpose lanes, which were found to be, on average, 8 minutes northbound in the A.M. peak and 4 minutes southbound in the P.M. peak.

OCR for page 127
Congestion Pricing Case Studies 135 In addition to traffic operations data, WSDOT also tracks the overall number of tolled trips made on the SR 167 HOT lanes. This information is generated by the automated toll collection system operated by WSDOT's toll vendor, Electronic Transaction Consultants (ETCC). Paid trips are broken down by time, day, and direction of travel, as well as toll rate. WSDOT also tracks toll revenue, which it generally reports as a monthly total. WSDOT often presents revenue data together with operational costs for the SR 167 facility, which include monitoring, shared main- tenance, enforcement, transaction processing, emergency response, customer service, and traf- fic management center and tolling operations. As of early 2010, average monthly operational costs for the SR 167 were approximately $97,600 and exceeded average monthly revenues of $32,700 by a factor of three. However, WSDOT has anticipated that over the 4-year pilot, over- all expenses would be covered by toll revenues and is projecting that revenues will begin to exceed expenses in early 2011. Nonetheless, as discussed later in this report, the objective of the SR 167 HOT-lane project is congestion reduction rather than revenue generation. WSDOT also tracks information provided by other agencies. This includes transit perform- ance data of travel times and ridership levels provided by Sound Transit, which operates two bus routes on the corridor, as well as the South Sounder commuter rail service. Sound Transit con- firms that travel times for its bus service did not change after the HOT conversion and that tran- sit ridership has actually increased 8.4 percent since the opening of the HOT lanes. WSDOT also tracks enforcement and safety data maintained by the Washington State Patrol. This includes information on occupancy and toll violations, as well as information on crashes and instances where roadside assistance of any kind is provided, together with response times. It should be noted that the WSP has maintained an increased presence in the corridor since the conversion, a factor which needs to be considered when making before-and-after comparisons. WSDOT also monitors conditions on the SR 167 at its Traffic Management Center using remote control cameras and data collected from traffic speed and volume sensors. This information is dis- played on a dashboard showing multiple tracking metrics, including traffic volumes, lane speeds, and toll rates. If any anomalies are seen, Traffic Management Center staff coordinate with the WSDOT Maintenance. Lastly, WSDOT also uses the Good To Go! Customer Service Center data- base to compile additional information on motorists paying to use the lanes, including residential zip codes and trips by vehicle make. 7.3. Other Essential Data Gathering Activities WSDOT's performance monitoring program for the SR 167 HOT lanes has also included dif- ferent survey efforts to track various parameters. Some of this work was completed prior to the opening of the HOT lanes and some was completed following the conversion. In January 2007, WSDOT completed a study of social, economic, and environmental justice for the SR 167 HOT-lane conversion to review effects the project might have on communities along the corridor and the fairness and equity of the project. The study captured the findings of WSDOT's comprehensive outreach efforts associated with the conversion, including opinion surveys, open houses, and public outreach events. The study found that the conversion would provide drivers of all income levels with a new option to make faster and more reliable trips and that a cash payment program option for toll accounts would enhance access to the system for low-income drivers. In January 2009, WSDOT conducted two focus group sessions designed to complete earlier work the Department began in 2006. The earlier work, which involved six focus group sessions, gauged initial perceptions of the SR 167 HOT lanes and compared responses by low-income and typical drivers, as well as service employees or those who were self-employed. The January 2009

OCR for page 127
136 Evaluation and Performance Measurement of Congestion Pricing Projects focus groups helped WSDOT learn how the operation of the new HOT lanes was affecting drivers in general, specifically low-income drivers. The focus groups explored the following issues: Acceptance of the lanes as a congestion-management tool Use of and access to the HOT lanes Potential obstacles to HOT-lane use and the magnitude of those obstacles Equity issues related to access, mode use, opportunity, income and geography, and difference in perceptions and responses between people in low-income groups and others Difference in perceptions and responses to the lanes by people who have transponders and those who do not In May 2009, an online survey was sent to 22,000 Good To Go! account holders who had a valid e-mail address and had driven the SR 167 HOT lanes at least once. Some 3,000 responded. The intent of the survey was to gain information on the age and income profiles of drivers paying to use the lanes and determine whether it was consistent with the findings from WSDOT's earlier 2005 Baseline Survey Report. The 2009 user survey addressed issues ranging from general satis- faction, to opinions on the extension of the demonstration, access treatments, and the shields that HOV motorists with Good To Go! Tags use in their vehicle to avoid being charged for their trips. 7.4. Why Performance Evaluation Takes Place and How Performance Monitoring Data Is Used WSDOT uses the monitoring data it collects on the SR 167 HOT lanes for various purposes. These are described in further detail below. Maintaining Traffic Service and Speed Levels on the HOT Lanes. As described earlier, WSDOT uses dynamic tolling on the SR 167, where toll levels are adjusted every 5 minutes in order to maintain traffic service and speed levels on the HOT lanes using real-time information on travel conditions in the corridor. The algorithm used to calculate toll rates on the SR 167 HOT lanes is proprietary to WSDOT's system operator, ETCC, and relies on real-time information on speeds, traffic volumes, and the distribution of non-paying HOV and tolled SOV vehicles on the facility. The algorithm--which some industry sources believe is the most sophisticated in use today in the United States--also takes into account monthly incidents on the lanes.5 Each of these factors is governed by coefficients that can be adjusted to alter their influence on the toll rate. The algorithm adjusts toll rates based on volumes and speed data, together with the rates at which volumes and speeds were changing. The toll rate is adjusted in 5-minute intervals and is driven by changes between the number of new vehicles actually entering the facility and the num- ber of vehicles predicted by the algorithm. Toll rates can vary between a low of $0.50 and a high of $9.00. If conditions on the SR 167 exceed the $9.00 maximum toll, the facility reverts to HOV- only operation. During its first year of operation, the average toll rate on the SR 167 was $0.96, and following the adjustments to the dynamic-pricing algorithm, the highest toll paid to use the lanes was $2.25, which occurred in April 2009. Fulfilling Legislatively Mandated Reporting Requirements. State legislation enabling the 4-year HOT demonstration on the SR 167 requires that WSDOT provide an annual report to the Washington Transportation Commission and the State Legislature on the operations of the facility. WSDOT is required to provide data on the use of the HOT lanes and review effects on 5This approach is different from the dynamic pricing system used by MnDOT on the I-35W and I-394 MnPASS lanes, which uses a look-up table that has established toll rates based on speeds and volumes.

OCR for page 127
Congestion Pricing Case Studies 137 efficiency and safety in the corridor, transit effectiveness, vehicle and person movements by mode, and equity issues. WSDOT is also required to provide financial data that demonstrates to what extent project proceeds are able to support other transportation services and improvements. The metrics used by WSDOT to document the performance of the SR 167 HOT-lane demonstra- tion have been selected to enable the Department's ability to fulfill these reporting requirements. WSDOT prepared 6- and 8-month performance summary reports, in addition to its First Annual Performance Summary for the SR 167 HOT lanes. All these documents are available to the public on WSDOT's SR 167 website, together with other technical reports, at the following location: Improving Operational Performance. The performance monitoring and user satisfaction data WSDOT collects enables it to assess the operational performance and safety of the HOT lanes and identify potential adjustments to them. As mentioned earlier, there are two challeng- ing situations that WSDOT has had to address with the SR 167 conversion: access to the facility and providing transponder shields to HOV motorists who have Good To Go! tags in their vehi- cles for use on the Tacoma Narrows Bridge. As a result of its survey work and focus group sessions, WSDOT has provided additional sig- nage with information on the location of upcoming access and egress points to and from the HOT lanes. The purpose of this change was to address confusion over these locations, exacer- bated by HOV users being accustomed to having continuous access in or out of the lanes at any point prior to the conversion. In addition, WSDOT's outreach efforts have focused on the effectiveness and ease of use of the tag shields. WSDOT officials had to take into account the timing of the new Tacoma Nar- rows Bridge opening which occurred in July 2007, just 10 months before the activation of the SR 167 HOT conversion. Because the new bridge is tolled, nearly all regular bridge users have obtained Good to Go! transponders. For example, there is a 96-percent penetration rate of transponder users in the Gig Harbor zip code--a city just adjacent to the entrance to the Tacoma Narrows Bridge. However, when the SR 167 conversion took place, no HOV users who had obtained a transponder for use on the bridge had the transponder shield required to avoid being tolled on the HOT lane. This situation introduced a significant outreach challenge for the SR 167 conversion. Documenting Changes in Travel Behavior and Traffic Conditions. The performance mon- itoring data documents changes in travel behavior by different user groups and the resulting changes in operational and congestion conditions on the SR 167 corridor. The improvements in congestion levels on the SR 167 as a result of the conversion are dramatic. WSDOT's before- and-after monitoring data during the A.M. and P.M. peak periods for 2007 and 2009 documents a 21.5-percent increase in average speeds on the general-purpose lanes and an 11-percent increase in average volumes. Speeds also increased 6 percent on the HOT lanes, which also saw a 4-percent increase in northbound volumes during the A.M. peak and stable volumes south- bound during the P.M. peak. However, because SR 167 provides two general-purpose lanes and one HOT lane in each direction, it would be anticipated that a volume lane movement from the general-purpose lanes to the HOT lanes would immediately result in increased speeds in the general-purpose lanes. Validating the Case for Congestion Pricing. Lastly, the collective data derived from the performance monitoring program enables WSDOT to validate the performance of the SR 167 HOT lanes to its stakeholders. This will be essential for the decision whether to extend the operation of the SR 167 lanes beyond the demonstration period's May 2012 expiration. It will also be essential to WSDOT's plans to introduce congestion pricing on the SR 520 Evergreen Point Floating Bridge, and possibly the I-90 Lake Washington crossing.

OCR for page 127
138 Evaluation and Performance Measurement of Congestion Pricing Projects Congestion Pricing Case Studies 139 Table 7-1. Washington State Department of Transportation SR 167 HOT Lanes summary matrix.

OCR for page 127
140 Evaluation and Performance Measurement of Congestion Pricing Projects 7.5. What Additional Performance Metrics or Data Would Be Helpful to WSDOT or Other Agencies Considering Congestion Pricing? WSDOT has a well-established culture of collecting comprehensive performance monitoring data, and the SR 167 HOT-lane facility is no exception. While WSDOT officials had access to comprehensive real-time traffic data derived from an extensive network of loop detectors and are accustomed to conducting before-and-after analysis for new improvements, they found it challenging to identify the right combination of performance metrics that would make a com- pelling case for congestion pricing's use. WSDOT officials believed that they were on their own to identify the best set of metrics to justify the need for and to track the performance of conges- tion pricing in the state. They also found that they lacked standard data on priced facilities in other locations for comparison with their own state. As a result of these gaps, WSDOT officials helped to initiate the effort to undertake the research performed in NCHRP 08-75 and hope that the findings of the study will help fill this void. One particular challenge cited by WSDOT officials has been identifying appropriate measures of travel reliability on the SR 167 corridor. While WSDOT has done an effective job of commu- nicating improvements in travel speeds and throughput as a result of the conversion, it remains to be seen whether its reliability metric of the 95th percentile end-to-end travel time carries the same impact. Communicating the meaning of the 95th percentile travel time metric to the pub- lic is also challenging. Another major challenge that WSDOT has faced with the SR 167 demonstration is that the intent of the conversion was not to generate revenue but to manage the operation of its existing infrastructure to improve traffic service, travel speeds, and the overall efficiency of the SR 167 corridor. Even so, the enabling legislation for the SR 167 demonstration requires WSDOT to report on the "ability to finance improvements and transportation services through tolls [col- lected on the SR 167 HOT lanes]." The reality is that the SR 167 HOT lanes operate at a deficit. Operating costs exceed average monthly toll proceeds of approximately $32,700 by a factor of three. This may cause elected officials and the public to question the rationale behind the con- version. However, the reality is that for a modest investment of $60,000 per month, or $720,000 per year, WSDOT has bought a 21.5-percent increase in average peak-period speeds on the con- gested general-purpose lanes and an 11-percent increase in average volumes. This leaves WSDOT with the challenge of communicating what the cost of implementing physical enhance- ments to SR 167 would have to have been to achieve the same congestion reduction effect as the HOV-to-HOT conversion.