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SECTION V--DESCRIPTION OF STRATEGIES need to work together and coordinate their safety programs in metropolitan areas, regions, and throughout the state. Strategies Detailed in Other Emphasis Area Guides Bicyclists move along and across all types of road facilities. The strategies in this guide attempt to reflect that by addressing a wide range of facility elements and roadway locations. However, there are other emphasis areas that address roadway features, which also relate to bicyclist safety. Further details on other applicable strategies may be found in the companion guides for unsignalized intersections, signalized intersections, older drivers, and pedestrians. Objective A--Reduce Bicycle Crashes at Intersections Strategy A1: Improve Visibility at Intersections (T) General Description Improving the visibility at intersections will enhance the safety of bicyclists and all other users traveling through the intersections. The two primary purposes for improving the visibility at intersections are: To make drivers and bicyclists more aware they are approaching an intersection so they are better prepared to comply with the traffic control devices and rules of the road at the intersection To provide drivers and bicyclists better views of one another to avoid potential conflicts. The visibility at intersections can be enhanced by improving the sight distance/sight lines near the intersection and/or by improving the conspicuity of traffic control devices at and near intersections. For example, improving the visibility at intersections could involve: Increasing the sight distance along the approach to an intersection so that drivers have a better view of the geometric and cross sectional features of the intersection; Clearing sight triangles so that users have better views of vehicles operating on side streets; Improving the visibility of traffic control devices which could involve removing vegetation or other roadside objects that obstruct the view of signs and signals or improving the conspicuity of traffic control devices (e.g., installing larger signs, additional signal heads, larger signal lenses, or signal backplates); or Improving the lighting along the approaches to the intersection and at the intersection proper. This strategy is related to several objectives and strategies provided in companion guides, in particular the guides that address reducing collisions at unsignalized (http://safety. transportation.org/guides.aspx?cid=26) and signalized (http://safety.transportation.org/ guides.aspx?cid=33) intersections and the guide that addresses collisions involving older drivers (http://safety.transportation.org/guides.aspx?cid=30). The reader is directed to V-7

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SECTION V--DESCRIPTION OF STRATEGIES these companion guides for more detailed information related to improving the visibility at intersections. The related objectives and strategies in the companion guides are as follows: NCHRP Report 500, Volume 5: A Guide for Addressing Unsignalized Intersection Collisions Objective 17.1 C--Improve sight distance at unsignalized intersections Strategy 17.1 C1: Clear sight triangles on stop- or yield-controlled approaches to intersections Strategy 17.1 C2: Clear sight triangles in the medians of divided highways near intersections Strategy 17.1 C3: Change horizontal and/or vertical alignment of approaches to provide more sight distance Strategy 17.1 C4: Eliminate parking that restricts sight distance Objective 17.1 E--Improve driver awareness of intersections as viewed from the intersection approach Strategy 17.1 E1: Improve visibility of intersections by providing enhanced signing and delineation Strategy 17.1 E2: Improve visibility of the intersection by providing lighting Strategy 17.1 E3: Install splitter islands on the minor-road approach to an intersection Strategy 17.1 E4: Provide a stop bar (or provide a wider stop bar) on minor-road approaches Strategy 17.1 E5: Install larger regulatory and warning signs at intersections Strategy 17.1 E8: Provide supplementary stop signs mounted over the roadway Strategy 17.1 E11: Install flashing beacons at stop-controlled intersections Objective 17.1 G--Improve driver compliance with traffic control devices and traffic laws at intersections NCHRP Report 500, Volume 12: A Guide for Reducing Collisions at Signalized Intersections Objective 17.2 C--Improve Sight Distance at Signalized Intersections Strategy 17.2 C1: Clear Sight Triangles Strategy 17.2 C2: Redesign Intersection Approaches Objective 17.2 D--Improve Driver Awareness of Intersections and Signal Control Strategy 17.2 D1: Improve Visibility of Intersections on Approach(es) Strategy 17.2 D2: Improve Visibility of Signals and Signs at Intersections Objective 17.2 E--Improve Driver Compliance with Traffic Control Devices NCHRP Report 500, Volume 9: A Guide for Reducing Collisions Involving Older Drivers Objective 3.1 B--Improve the Roadway and Driving Environment to Better Accommodate Older Driver's Special Needs Strategy 3.1 B7: Improve lighting at intersections, horizontal curves, and railroad grade crossings A treatment that helps to improve the visibility at intersections which is unique to bicycles and bicycle facilities involves installing bicycle racks near street corners (Zegeer et al., 1994). This type of treatment has been implemented at several intersections in Germany where cars parked too close to the intersection created a visibility problem for motorists on the side streets. Installing bike racks on the street corners physically prevented cars from parking close to the intersection and opened up the sight distance for side street traffic. With this type of treatment, it is probably desirable to install barriers to protect bicyclists near the bike racks or potentially install the bike racks in conjunction with the construction of a bulbout at the intersection. V-8

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SECTION V--DESCRIPTION OF STRATEGIES Another visibility issue unique to bicycles is the ability of bicyclists to see the signal heads from their typical location, in most cases the right edge of the roadway. For programmed visibility heads, this may require that the signal heads be adjusted slightly to be visible to bicyclists (see Strategy A2). Improving the visibility at path/roadway intersections is also important. In an effort to improve the crossing situations for trail users at path/roadway intersections, Maryland DOT has installed several innovative treatments, which are discussed in detail in Appendix 1. Strategy A2: Improve Signal Timing and Detection (T) General Description At signalized intersections bicycle traffic should be considered during the development of the traffic signal timing. In many cases of mixed flow traffic, bicyclists can safely travel through a signalized intersection when the phasing plan is timed strictly to accommodate motor vehicles; however, the signal timing at all signalized intersections where bicycle traffic is present or is anticipated should be reviewed to determine if bicycle traffic is sufficiently accommodated. In those cases where it is not, the signal timing should be modified. When the signal is actuated, detection of bicycles is crucial for safety. Several ways to improve signal timing and detection to better accommodate bicycle traffic include: Providing an adequate clearance interval Providing a leading bicycle phase or bicycle-only phase (which will also involve installation of bicycle signals) Providing sensors that detect the presence of a bicycle (which may also involve marking the roadway to indicate the optimum location for bicycle detection) The AASHTO Bicycle Guide (1999) provides guidance on calculating adequate clearance intervals for bicyclists. The total clearance interval (i.e., yellow change interval plus red clearance interval) is calculated as: v w+l y + rclear tr + + 2b v y = yellow interval(s) rclear = red clearance interval(s) tr = reaction time (1.0 s) v = bicyclist speed (mph) b = bicyclist's braking deceleration (4 to 8 ft/s2) w = width of crossing (ft) l = bicycle length (6 ft) AASHTO indicates that approximately 98 percent of bicyclists should be able to clear an intersection assuming the following speeds: 19 km/h (12 mph) for advanced bicyclists, 13 km/h (8 mph) for basic bicyclists, and 10 km/h (6 mph) for children bicyclists. These speeds provide guidance for calculating clearance intervals in the absence of field data. However, recent research by Rubbins and Handy (2005) presents data on bicycle clearance times for V-9

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-2 different intersection distances that indicates Bicycle Signal Head bicyclists' speeds are considerably slower than the (http://www.bayareatrafficsignals.org/toolbox/ assumed speeds recommended by AASHTO, Tools/ToolboxPhotos/BikeSigHead.jpg) meaning longer clearance times for bicyclists may be necessary. Providing a leading bicycle phase in the signal timing plan gives priority to bicyclists and enables bicyclists to at least establish their presence within, if not clear, the intersection which should reduce the potential for conflicts with motor vehicle traffic. During a bicycle-only phase, the mixed traffic is separated to facilitate the flow of all types of traffic. A variation of the bicycle-only phase is a bicycle scramble phase which allows bicyclists from all intersection approaches to cross an intersection at the same time. Providing a leading bicycle phase or bicycle-only phase requires a separate bicycle signal (Exhibit V-2) to direct bicycle traffic through the intersection and would only be implemented at intersections with marked bicycle lanes or separated paths. It is possible that bicycle signal heads could be installed with pedestrian heads, or potentially in conjunction with pedestrian count down signals. Many actuated signal systems were designed and installed without attention to their effects on bicyclists (Williams et al., 1998). As a result, bicyclists may find it frustrating and impossible to get a green indication. Providing a detector that senses the presence of a bicycle will encourage more bicyclists to follow the rules of the road at actuated signals rather than disregard the signal. A bicycle detector pavement marking may be placed on the pavement indicating the optimum position for a bicycle to actuate the signal (Exhibit V-3). A EXHIBIT V-3 bicycle detector pavement marking should be provided when bicycle Example of Bicycle detection cannot be reliably achieved while riding along the expected Detector Pavement path of bicyclists, particularly when the loop detector is not apparent. Marking (USDOT, 2003) Bicycle detector pavement markings are also useful on actuated side street approaches and actuated left-turn lanes, where motor vehicle traffic may be infrequent, and bicyclists have difficulty getting a green indication. Information on Agencies or Organizations Currently Implementing this Strategy In 2004, the city of Portland, Oregon, installed a bicycle-only traffic signal at the intersection of Interstate Avenue and Oregon Street. For more details on this installation, visit their website at http://www.trans.ci.portland.or.us/bicycles/Scramble.htm. The city of Davis, California, has also installed several bicycle signals, which seem to have reduced the number of bicycle/motor vehicle crashes, although no scientifically sound before-after evaluations have been conducted to prove their safety effectiveness. V-10

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-4 Strategy Attributes for Improving Signal Timing and Detection. (T) Attribute Description Technical Attributes Target This strategy concerns bicycle-related problems with traffic signal installations. It focuses on signalized intersections where bicyclists have difficulty clearing the intersection before the cross traffic receives a green indication. In most cases, bicyclists have difficulty clearing intersections of multilane roads (4, 5, 6+ lanes), not single lane roadways (Tan, 1996). This strategy also focuses on actuated signal installations that do not sense the presence of bicycles. Expected It has been estimated that bicycle clearance-time crashes, where a motor vehicle hits a Effectiveness bicyclist who has entered a signalized intersection lawfully but has been unable to clear the intersection before the signal changes, constitute approximately 6 percent of urban bicycle/motor vehicle crashes (Wachtel et al., 1995). No studies have been conducted to evaluate the decrease (or increase) in bicycle/motor vehicle crashes due to modifying the clearance interval to better accommodate bicycle traffic, but it is expected that by better accommodating bicyclists during the clearance interval, these types of bicycle/motor vehicle crashes will decrease. Korve and Niemeier (2002) performed a benefit-cost analysis of adding a bicycle phase at a single signalized intersection in the city of Davis, California. One of the measures considered in the analysis was the crash history. Although a formal before and after evaluation was not performed, the crash history showed a total of 14 accidents during the 35 months prior to the signal modification and 2 accidents during the first 35 months after the signal modification. An earlier study was also conducted in 1996 by the city of Davis, California, on the use of bicycle signal heads (Pelts et al., 1996). They installed bicycle signal heads at a single signalized intersection due to the volumes of bicycles interacting with motor vehicles. The intersection was a T-intersection with a three-phase signal. The bicycle signal heads were installed for northbound and southbound traffic to provide bicyclists a separate signal phase for movements through the intersection. Based upon the results of a before and after questionnaire of both bicyclists and motorists, most respondents noted a marked increase in safety through the intersection. The accident history showed that in 3 years before modification 14 crashes occurred at the intersection, and over 50 percent of these crashes involved either bicyclists or pedestrians. In the 16 months following the treatment, 2 crashes occurred, and neither involved a bicyclist or a pedestrian. No studies have been conducted on the safety effectiveness of providing bicycle detection at actuated signals. However, it is expected that this type of treatment will increase bicyclist compliance with traffic signals, which should reduce the number of bicycle/motor vehicle crashes that result when bicyclists ride out into an intersection during a red indication, rather than yielding the right of way to motor vehicle traffic on the cross street. Keys to Success While there may be a need to better accommodate bicyclists during the clearance interval, there is also a need to balance operations and safety. Especially at wider intersections, clearance intervals required for bicyclists are much longer than those required for motor vehicles, but long clearance intervals have a number of disadvantages (see discussion on Potential Difficulties). The Manual on Uniform Traffic Control Devices for Streets and Highways (MUTCD) suggests that the yellow change interval should have a duration of approximately 3 to 6 seconds, and the red clearance interval shall not exceed 6 seconds (USDOT, 2003). It may be (based upon the assumptions made during the calculations for bicycle clearance interval) that bicyclists cannot clear the intersection during the clearance interval that is initially provided in the signal timing V-11

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-4 (Continued) Strategy Attributes for Improving Signal Timing and Detection. (T) Attribute Description Technical Attributes plan. However, it is key that bicyclists' needs, as well as the needs of all highway users, be balanced when finalizing signal timing plans. Providing a leading bicycle phase or a bicycle-only phase requires the installation of bicycle signals. Similar to the traffic signal warrants that are already provided in the MUTCD, development of a bicycle signal warrant or policy that may be used to justify the installation of a bicycle signal would provide credibility to the treatment. For example, the California Traffic Control Devices Committee (CTCDC) developed a bicycle signal warrant that takes into consideration both bicycle and motor vehicle volumes, accident history, and the geometrics of the intersection (Appendix 2). When a leading bicycle phase is provided to facilitate left-turning bicyclists, installation of a bicycle box at the head of the intersection is also necessary. Being in the bicycle box in front of the queued motor vehicles, bicyclists are more visible to motorists, which tends to reduce the number of bicycle/motor vehicle conflicts (see Strategy A4). The key for providing bicycle detection is to install a system that can reliably detect bicycles and provide inputs to traffic signals for call and extend functions. Several types of systems are available for detecting bicycles. Most of the systems are passive devices such as loop detectors and infrared or video detection systems. Others are active, such as the bicycle push-button that is similar to those used by pedestrians (Nabti and Ridgway, 2002). Several recent studies have been conducted to evaluate the ability of these various technologies to detect bicycles. The Federal Highway Administration (FHWA) and Minnesota Department of Transportation funded a study to identify the applications and evaluate the accuracy of different non-intrusive technologies in detection of non-motorized traffic, namely bicyclists and pedestrians. Five types of technologies were evaluated (USDOT, 2003): passive infrared/ultrasonic, infrared, microwave, video, and inductive loop. Noyce and Dharmaraju (2002) conducted a similar study for Massachusetts Highway Department. The objective of this study was to identify and evaluate existing technologies that may accurately and efficiently detect, count, and classify non- motorized modes of transportation (i.e., bicyclists and pedestrians). Microwave, ultrasonic, acoustic, video image processing, piezoelectric, passive infrared, active infrared, magnetic and traditional (inductive loops and pneumatic traffic classifiers) were considered. The active infrared technology was evaluated most in depth and was found to be very effective in detecting bicyclists. Several sources such as Wachtel (2000) and Williams et al. (1998) provide guidance on inductive loop systems that are sensitive enough to detect bicycles. Another key at signalized intersections is that bicyclists must be able to see the signal heads, in most cases from the right edge of the roadway. For programmed visibility heads, this may require that the signal heads be adjusted slightly to be visible from typical bicyclist locations. Finally, coordinated traffic signals are designed to facilitate vehicular traffic flow. To better accommodate bicyclists, it may be possible to coordinate the signals based upon bicycle speeds rather than motor vehicle speeds. This could serve as a traffic calming measure, reducing the advantage of motor vehicles traveling faster than the speed for which the signals are timed (Bicycle Advisory Committee, 1997). This type of treatment would only be appropriate on low-speed facilities where it makes sense for motor vehicles to slow to the speeds of bicyclists. V-12

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-4 (Continued) Strategy Attributes for Improving Signal Timing and Detection. (T) Attribute Description Technical Attributes Potential Difficulties To accommodate bicyclists, clearance intervals may need to be lengthened. However, long clearance intervals have several disadvantages (Wachtel et al., 1995): Cause extra delay to traffic May encourage motorists to enter the intersection, believing they are protected May confuse waiting drivers who do not understand why the signal fails to change Similar to extending the clearance interval, providing a leading bicycle phase or bicycle- only phase may cause the intersection to operate less efficiently for motor vehicle traffic. Other disadvantages of a leading bicycle phase and/or a bicycle-only phase include (Nabti and Ridgway, 2002): Cost of installation and on-going operation and maintenance of additional signal hardware may be a concern. Unfamiliar drivers may be confused or uncertain about the intended purpose of signals. Bicycle-only traffic signals can also greatly increase intersection delay to bicyclists who could otherwise have proceeded with the other traffic in the same direction. In addition, bicycle signals may promote non-uniformity of traffic control for bicyclists. Bicyclists will be expected to operate in a significantly different manner at the intersections controlled by these signals (Moeur, 1999), and it is possible that at a conventional street intersection any bicycle-only traffic signal that restricted bicycle crossing when parallel motor vehicle traffic had a green indication would be ignored. Depending upon the type of technology used to detect bicycles, vandalism could be an issue if the system is installed above ground. Due to their slower speeds, bicycles may adversely affect the capacity and operation of motor vehicles at single point urban interchanges (SPUIs). The required green and all- red clearance intervals necessary for a bicyclist to clear most SPUIs are substantially longer than what is needed for motorists. The required extended signal timing increases delay for motorists. To better accommodate bicyclists, SPUIs should be designed as compactly as possible (Qureshi et al., 2004). Appropriate Measures Appropriate process measures may include (a) the percentage of signalized and Data intersections where bicyclists can safely cross the intersection during the clearance interval as calculated based upon the equation provided, (b) the percentage of actuated signals that have sensors capable of reliably detecting bicycles, and (c) the number of signals that have a leading bicycle phase or bicycle-only phase. Appropriate measures used to evaluate the safety effectiveness of the signal modifications include (a) the number of bicycle/motor vehicle crashes that are correctable due to modifications in signal timing and/or detection, (b) the change in level of service (i.e., delay) to motor vehicle traffic due to modifications in signal timing, and (c) the percentage of bicyclists who clear the intersection based on the clearance interval. Bicycle exposure data is also critical (i.e., bicycles per hour that enter the respective intersections) for determining the number of bicycle/motor vehicle crashes that could potentially be reduced if this treatment were implemented. V-13

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-4 (Continued) Strategy Attributes for Improving Signal Timing and Detection. (T) Attribute Description Technical Attributes Associated Needs Field observations may be desirable to calculate clearance intervals based upon local conditions. Bicycle and motor vehicle volumes will also be necessary to develop a modified signal timing plan. The agencies responsible for maintaining traffic signal systems will incur additional maintenance work if new hardware is installed in the field. It may also be necessary to install additional signs in association with bicycle signals. In addition, bicycle signals are not an accepted traffic control device in the MUTCD. An agency should follow the provisions outlined in Section 1A.10 of the MUTCD for design, application, and placement of traffic control devices that are not adopted in the most recent edition of the MUTCD. In addition, it would be desirable to develop warrants for bicycle signals, similar to the 8 traffic signal warrants currently provided in the MUTCD. If bicycle detection is going to be installed, a decision needs to be made where bicyclists will likely be in order to detect them. A decision needs to be made whether detection will occur at the intersection proper and/or in advance of the intersection on the approach. A Bicycle Signal Actuation sign (R10-22) (Exhibit V-5) may also be installed where markings are used to indicate the location where a bicyclist is to be positioned to actuate the signal (USDOT, 2003). The MUTCD indicates that if the Bicycle Signal Actuation sign is installed, it should be placed at the roadside adjacent to the marking to emphasize the connection between the marking and the sign. EXHIBIT V-5 Bicycle Signal Actuation Sign (USDOT, 2003) Finally, agencies may need to develop a formal policy for improving signal timing and detection. Such a policy could involve one or more of the associated issues (i.e., providing adequate clearance intervals for bicyclists, providing a bicycle signal with a lead bicycle phase or bicycle-only phase, or providing bicycle detection). Organizational and Institutional Attributes Organizational, Agencies should make it mandatory that bicyclists be considered during the Institutional and development of all signal timing plans. Policy Issues Issues Affecting It may be desirable to collect field data (i.e., clearance times and exposure data) at local Implementation Time sites. Because bicycle signals and/or bicycle detection are not typical treatments around the country, agencies may find it desirable to invest some time in researching previous applications and/or available technologies. Bicycle signals may not be supported by local traffic laws, so legislative action may be necessary which could impact implementation time (Nabti and Ridgway, 2002). In V-14

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-4 (Continued) Strategy Attributes for Improving Signal Timing and Detection. (T) Attribute Description Organizational and Institutional Attributes addition, if a formal policy is required to guide installation/implementation of such a treatment, cultural effects may impact acceptance of the policy. For example, decision makers may have an underlying assumption that all bicyclists proceed through signalized intersections when available gaps in traffic are present rather than waiting for the right of way from the green signal indication. If decision makers have such an assumption, they may question the need to adopt a formal policy on bicycle detection. Costs Involved Data collection costs may be incurred to collect clearance intervals and exposure data. Capital costs may also be incurred for poles, bicycle signal heads, detection hardware, and detection software. Installation and maintenance costs will also be involved. Appendix 3 provides cost estimates of several ITS technologies that can be used for bicycle detection. Training and Other If ITS technologies are used for bicycle detection, personnel may need initial training on Personnel Needs the software and how to calibrate the detector systems. Legislative Needs Local traffic laws may need to be modified to support bicycle signals. Other Key Attributes None identified Appendix 4 provides additional information on other agencies' experiences with implementing this strategy. Strategy A3: Improve Signing (T) General Description Signs are placed within the right of way to provide regulation, warning, and guidance information to road users. This strategy focuses on providing additional regulatory and warning signs to improve bicycle safety at intersections and on modifying existing signage. The AASHTO Bicycle Guide (1999) and MUTCD (2003) should be consulted concerning bicycle-related signs that can improve safety at intersections. Several regulatory and warning signs that should be considered for improving safety include: Begin Right Turn Lane Yield To Bikes (R4-4) Intersection Warning Signs (W2 Series) Advance Traffic Control Signs (W3 Series) Bicycle Warning Sign (W11-1) The Begin Right Turn Lane Yield To Bikes sign (Exhibit V-6) may be installed at intersections with marked bicycle lanes and right turn only lanes. At intersections with exclusive or channelized right-turn lanes, bicyclists are at risk because motor vehicles entering the exclusive or channelized right-turn lane must weave across the path of bicycles traveling straight through the intersection. The MUTCD indicates that where motor vehicles entering an exclusive right- turn lane must weave across bicycle traffic in a bicycle lane, the Begin Right Turn Lane Yield V-15

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-6 To Bikes sign may be used to inform both the driver and the Begin Right Turn Lane Yield bicyclist of this weaving area (USDOT, 2003). This sign, in to Bikes Sign(USDOT, 2003) conjunction with the associated pavement markings, is intended to encourage motorists and bicyclists to cross paths in advance of intersections in a merging fashion (Hunter et al., 1999) and encourage bicyclists to follow the rules of the road (i.e., through- vehicles, including bicyclists, proceed to the left of right-turning vehicles) (WSDOT, 2001). The primary advantages of having through bicyclists and right-turning motor vehicles cross prior to the intersection include: Moving this conflict away from the intersection and other conflicts Enabling the motorist to pass a bicyclist rather than ride side-by-side due to the difference in travel speeds Exhibit V-7 illustrates several signs for bicycle lanes at intersections where the bicycle lanes continue to the left of the right-turn only lanes. These signs convey to both motorists and bicyclists the proper channelization through the intersections. Intersection warning signs (Exhibit V-8) may be used on a roadway, street, or shared-use path in advance of an intersection to indicate the presence of an intersection and the possibility of turning or entering traffic (USDOT, 2003). The MUTCD states that when engineering judgment determines that the visibility of an intersection is limited on a shared-use path approach, intersection warning signs should be installed. However, intersection warning signs should not be used where the shared-use path approach to an intersection is controlled by a STOP sign, YIELD sign, or a traffic control signal. Advance traffic control signs include Stop Ahead (W3-1), Yield Ahead (W3-2), and Signal Ahead (W3-3) (Exhibit V-9). These signs shall be installed on an approach to a primary traffic control device that is not visible for a sufficient distance to permit the road user to respond to the device (USDOT, 2003). These signs may also be used for additional emphasis of the primary traffic control device even when the visibility distance to the device is satisfactory. A Bicycle Warning sign (Exhibit V-10) may be used to alert road users to unexpected entries into the roadway by bicyclists. In many cases, this sign may be installed at the intersection of a shared-use path and a roadway. This sign may be installed in advance of the specific crossing point, and a supplemental plaque with the legend "Ahead" or "XXX Feet" may be used with the sign. This sign may also be installed at the location of the crossing. When used at the location of the crossing, the Bicycle Warning sign shall be supplemented with a diagonal downward pointing arrow (Exhibit V-10) plaque to show the location of the crossing. In addition to installing regulatory and warning signs, consideration should be given to whether existing signs and traffic control are the most appropriate for the intersection. For example, consideration should be given to changing STOP signs to YIELD signs where appropriate (see The Bicycle Matrix at http://www.bicyclinginfo.org/matrix/counter2. cfm?record=16&num=2a). Bicyclists are often reluctant to stop at STOP signs because they lose all their momentum. As a result, there is a tendency for bicyclists to treat STOP signs as YIELD signs if they occur quite frequently and are at intersections with little traffic. Danger arises when bicyclists behave this way at a busier intersection and fail to yield to motor vehicle traffic. One solution is to reevaluate the use of STOP signs in the community to determine whether some could be changed to YIELD signs, leaving STOP signs at the intersections V-16

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-7 Signing for Bicycle Lanes Adjacent to Right-Turn Only Lanes (Chicago DOT, 2002; Caltrans, 2005) V-17

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-27 Bicycle Crossing of Interchange Entrance Ramp where a Bicycle Lane Becomes a Separated Path (Oregon DOT, 1995) Roadway width is excessive given the available crossing time. Crossing will be used by a number of people who cross more slowly (i.e., elderly, children, and persons with disabilities). Exhibit V-28 provides example specifications for a refuge area at a path/roadway intersection. V-38

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-28 Specifications for a Refuge Island at a Path/Roadway Intersection (AASHTO, 1999) EXHIBIT V-29 Strategy Attributes for Improving the Geometry (T) Attribute Description Technical Attributes Target When bicycle safety concerns cannot be sufficiently addressed through traffic control (i.e., signing and pavement markings), modifications to the geometrics should be considered. Expected No accident studies have been performed that prove reducing the crossing distance at Effectiveness an intersection is a safety benefit for bicyclists. However, based upon exposure time, it is reasonable to expect that such a treatment improves bicycle safety, and research by Landis et al. (2003) on intersection level of service for bicyclists indicates that bicyclists feel safer crossing shorter distances. Concerning the expected safety benefits of realigning the roadway, a group of experts concluded from a review of the literature that realigning intersection approaches to reduce or eliminate intersection skew improves motor vehicle safety at unsignalized intersections along two-lane rural highways (Harwood et al., 2000). Skew angle is less of a safety concern at signalized intersections since the traffic signal separates most movements from conflicting approaches. The expert panel concluded the safety effectiveness of realignment is as follows for total motor vehicle crashes: AMF = exp (0.0040 SKEW) For three-legged intersections and AMF = exp (0.0054 SKEW) For four-legged intersections where: AMF = Accident modification factor SKEW = Intersection skew angle (degrees), expressed as the absolute value of the difference between 90 degrees and the actual intersection angle. V-39

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-29 (Continued) Strategy Attributes for Improving the Geometry (T) Attribute Description Technical Attributes Multiplying the AMF by the proportion of bicycle/motor vehicle accidents at an intersection would give an indication of the expected number of bicycle/motor vehicle accidents that would be reduced due to this treatment. Interchange areas are high conflict locations for bicyclists because of the merging and weaving that occurs with motor vehicle traffic. No accident studies have been conducted on the safety benefits of modifying the geometrics near on- and off-ramps for bicyclists. Uniformly applying the optional treatments would increase both driver and bicyclist expectancy, which in turn is expected to improve bicycle safety. Although no accident studies have investigated the safety effectiveness of raised medians on bicycle safety, raised medians have provided significantly lower pedestrian crash rates on multi-lane roads, compared to roads with no raised median (Zegeer et al., 2002). It is reasonable to expect that raised medians would also benefit bicyclists at path/highway crossings. Raised refuge islands can also serve to calm traffic (i.e., reduce motor vehicle speeds), which is beneficial for bicyclists. Keys to Success The key to successfully applying this strategy is to identify candidate locations at which crash patterns exist that may be remedied by one of these various geometric improvements. Some of the optional treatments for improving bicycle safety near interchange areas have the bicyclist taking a path that is not necessarily the shortest distance through the interchange area for the bicyclist. A key to successful implementation is not to significantly increase the travel distance for bicyclists. Raised refuge islands should be considered where there are a limited number of gaps in the traffic stream and at intersections with long crossing distances. For example, AASHTO (2004) recommends that a refuge island be considered when the crossing distance exceeds 18 m (60 ft). Holding rails can also be installed so bicyclists do not have to put their feet down, thus making it quicker to start again. Finally, crossing islands must be visible to the motorist. This can be accomplished either with lighting (or illumination) or through retroreflective signs, pavement markings, or other materials (e.g., retroreflective tape can be installed along hand rails located within the median island to improve visibility). Potential Difficulties Several potential difficulties related to reducing the crossing distance for bicyclists are that it could negatively impact the level of service of the intersection and depending upon how the reduced crossing distance is achieved, it may decrease the separation distance between motor vehicles and between motor vehicles and bicyclists, which could negatively impact safety. When realigning a skewed intersection approach, it is possible to create such a sharp horizontal curve that the curve itself becomes a safety concern. Thus, the designer should be careful to avoid trading one safety concern for another. Realignment may also negatively affect adjacent properties. Because some of the optional treatments for improving bicycle safety near interchange areas are not necessarily the shortest distance through the interchange area for the bicyclist, some bicyclists may deviate from the bicycle facility. If it is not designed properly, a refuge island near an intersection could potentially be hazardous for all road users (i.e., bicyclists, pedestrians, and motorists). Thus, the designer should be careful to avoid trading one safety concern for another. Exhibit V-28 provides general specifications for a refuge island. V-40

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-29 (Continued) Strategy Attributes for Improving the Geometry (T) Attribute Description Technical Attributes Appropriate Measures A key process measure is the number of intersections where geometric improvements and Data were implemented to improve bicycle safety. Crash frequency and severity, by type, are key safety effectiveness measures. Separate analysis of crashes targeted by the improvement is desirable. The analysis should also investigate bicycle/motor vehicle crashes and strictly vehicular crashes separately. Crash frequency and severity data are needed. Both bicycle and traffic volume data are needed to represent exposure. Crash location data is also important, particularly in interchange areas. Associated Needs None identified. Organizational and Institutional Attributes Organizational, Highway agencies should ensure that their design policies for new or reconstructed Institutional and intersections incorporate these geometric considerations for bicyclists. Guidance should Policy Issues be provided on where one or more of these geometric considerations are appropriate. Issues Affecting Most of the options for modifying the geometry of an intersection to improve bicycle Implementation Time safety can be implemented in a relatively short time frame (i.e., 1 to 2 years). The exception is realignment of skewed intersections, which could potentially take as long as 4 years. At least 1 year is necessary to work out the details of intersection approach realignment and to communicate the plan to affected businesses and residents. Where relocation requires right-of-way acquisition or demolition of existing structures, an extensive project development process up to 4 years long may be required. Costs Involved The costs for this strategy will vary widely, depending upon the design. Reducing the crossing distance can be accomplished either through restriping the pavement markings or by reconstructing the intersection such that the physical distance between curbs is narrower. Obviously, restriping costs are minimal compared to the intersection reconstruction costs. Reducing or eliminating the skew angle of an intersection involves the realignment of at least one intersection approach. The cost of this type of construction project is usually high. Furthermore, additional right-of-way will generally need to be acquired. Costs for improvement to interchange areas should be relatively minimal, unless a separated path is provided. Costs for additional signing and pavement markings could be incurred. Costs for refuge islands and raised medians vary depending upon the design, site conditions, and the use of landscaping. Appendix 9 in NCHRP Report 500, Volume 10: Guide for Reducing Collisions Involving Pedestrians provides typical cost estimates. Training and Other None identified. Personnel Needs Legislative Needs None identified. Other Key Attributes None identified. V-41

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SECTION V--DESCRIPTION OF STRATEGIES Strategy A6: Restrict Right Turn on Red (RTOR) Movements (E) General Description Throughout the United States motorists are permitted to make a right turn on red (RTOR) movement unless prohibited by a posted traffic sign. The only exception to this rule is within New York City, where RTOR is generally prohibited unless otherwise permitted at specific locations by posted traffic signs. State RTOR laws generally require that drivers come to a complete stop and yield to approaching traffic before making a RTOR maneuver. The national policy permitting RTOR was instituted primarily to reduce fuel consumption following the energy crisis of 1973. Additional benefits of the RTOR policy include reduced vehicle delays and tailpipe emissions (Retting et al., 2002). Following the adoption of the national RTOR policy, significant increases in bicycle crashes at signalized intersections were reported (Preusser et al., 1982; Zador, 1984). The effects were more pronounced in urban and suburban areas than in rural areas that have fewer signalized intersections (Preusser et al., 1982). Preusser et al. (1982) also reported that in most cases bicyclists were approaching from the driver's right side and drivers frequently claimed they were looking to the left searching for a gap in traffic and never saw the bicyclists. The primary purpose of this strategy is not to restrict RTOR at all signalized intersections in an area or local jurisdiction. Rather, the purpose is to restrict RTOR movements at certain signalized intersections throughout the entire day or during portions of the day (e.g., during periods of peak bicycle activity). At signalized intersections with a history of bicycle/motor vehicle crashes resulting from RTOR movements, an analysis of the time of day of the crashes may provide justification for restricting RTOR movements throughout the entire day or during specified hours of the day. EXHIBIT V-30 Strategy Attributes for Restricting Right Turn on Red (RTOR) Movements (E) Attribute Description Technical Attributes Target This strategy is to be implemented at signalized intersections where a significant number of motorists have struck bicyclists while making a RTOR. The prohibition may be scheduled throughout the entire day or during specified hours. This strategy may be especially applicable to intersections located near schools. Expected Approximately 3 to 4 percent of all bicycle/motor vehicle crashes occur during a RTOR Effectiveness maneuver, and 6 percent of these crashes result in serious or fatal injuries (Tan, 1996). The expected number of bicycle/motor vehicle crashes that may be reduced by implementing this strategy is difficult to assess because it is an experimental treatment for improving bicycle safety. However, this strategy has been recommended for improving pedestrian safety based upon a field study by Retting et al. (2002). Similar to bicycle crashes, significant increases in pedestrian accidents at signalized intersections have been reported following the adoption of the national RTOR policy. Retting et al. (2002) report that traffic signs prohibiting RTOR during specified hours were very effective at increasing driver compliance with stop lines, reducing the number of drivers turning right on red without stopping, and reducing the number of pedestrians yielding V-42

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-30 (Continued) Strategy Attributes for Restricting Right Turn on Red (RTOR) Movements (E) Attribute Description Technical Attributes the right-of-way to turning vehicles. It seems reasonable to expect that restricting RTOR movements, even only during specified hours of the day (i.e., during periods of peak bicycle activity), would reduce the likelihood of bicycle/motor vehicle crashes resulting from RTOR movements. Keys to Success Keys to success include (a) identifying signalized intersections where bicycle/motor vehicle crashes resulting from RTOR movements have occurred, (b) determining whether the restrictions should be throughout the entire day or only during specified hours of the day (e.g., periods of peak bicycle activity), and (c) consistent enforcement of the restrictions. Potential Difficulties Depending upon how this strategy is implemented and whether any potential PI&E programs might be released with this strategy, motorists may become disgruntled at any inconvenience (i.e., increased delay) that they experience if they personally do not view or encounter any bicyclists at the respective intersections during the periods of restricted movement. Enforcing the RTOR restrictions could also be difficult. Appropriate Measures Key process measures include the number of signalized intersections where RTOR and Data movements are restricted. Key safety effectiveness measures include (a) the frequency and severity of bicycle/motor vehicle crashes resulting from all right turn movements at signalized intersections, (b) the frequency and severity of bicycle/motor vehicle crashes resulting from RTOR movements at signalized intersections, and (c) the percentage of vehicles that comply with the RTOR restrictions. Exposure data is also critical for measuring safety effectiveness. In particular, bicycle exposure data (i.e., bicycles per hour that enter the respective intersections) during the periods of restricted movement is important, as well as motor vehicle counts (i.e., number of right-turning vehicles per hour and number of RTOR movements per hour). RTOR bicycle problems begin with wrong-way riding so the percentage of bicyclists riding in the wrong direction of travel (i.e., wrong-way riding) is also an important safety measure that should be collected. Associated Needs An accident analysis that investigates the time of day of bicycle/motor vehicle crashes that resulted from right-turn movements and RTOR movements may help to establish specific hours for the RTOR restrictions. In the absence of accident data, conflict studies could be performed at intersections to identify where this strategy may be applicable. Bicycle exposure data should also be gathered to determine periods of peak bicycle activity. A PI&E program may be released in part to educate bicyclists about the inherent dangers of wrong-way riding and to educate motorists about the primary purpose for the RTOR restrictions so that they may be more understanding of the RTOR restrictions and comply better with the restrictions. Organizational and Institutional Attributes Organizational, None Identified Institutional and Policy Issues V-43

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-30 (Continued) Strategy Attributes for Restricting Right Turn on Red (RTOR) Movements (E) Attribute Description Organizational and Institutional Attributes Issues Affecting This strategy can be implemented in a relatively short timeframe (i.e., 3-6 months). The Implementation Time only issues affecting the implementation time are conducting respective accident analyses/ conflict studies and gathering exposure data (See Associated Needs section). It is assumed that the accident data are readily available in electronic format for analysis. Similarly, if a PI&E program was released in conjunction with this strategy, it could be developed in a short time period. Costs Involved Costs for implementing this strategy are relatively minimal. Associated costs would involve performing the accident analysis/conflict study and gathering exposure data. Gathering bicycle exposure data is often labor intensive and could require significant funds, depending upon the amount of data desired. Costs for a PI&E program may also be incurred. Finally, costs for supplying and maintaining the No Turn on Red signs and supplemental plaque (Exhibit V-31) showing the times of day that the restriction is in place will be incurred. EXHIBIT V-31 No Turn on Red Signs and Supplemental Plaques (USDOT, 2003) Training and Other The presence of law enforcement personnel may be required periodically to enforce Personnel Needs and encourage higher compliance from motorists. Possibly in conjunction with a PI&E program, law enforcement personnel can also educate bicyclists who may be riding the wrong-way through these intersections on the inherent dangers of wrong-way riding. Legislative Needs None identified. Other Key Attributes None identified. Strategy A7: Accommodate Bicyclists through Roundabouts (T) When used and designed properly, roundabouts have been proven to significantly reduce motor vehicle crashes (Persaud et al., 2001). However, bicyclists do not experience the same safety benefits at roundabouts as motorists, although the results are mixed. Shen et al. (2000) concluded that bicycle accident rates at roundabouts are 15 times those of motor vehicles, and surveys taken from bicyclists indicate that bicyclists find roundabouts significantly more stressful to negotiate than other forms of intersections, particularly on roads with heavy traffic. A Danish accident study conducted on 48 Dutch roundabouts found that 66 percent of all injured users were bicyclists (Jorgensen & Rundkorsler, 1991). Alternatively, V-44

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SECTION V--DESCRIPTION OF STRATEGIES a separate 1994 Danish study used a sample of 201 roundabouts and concluded that while they did not benefit as significantly as motor vehicles, bicycles and mopeds experienced a 44 percent reduction in the number of casualties (Schoon and Minnen, 1994). In considering these European studies, it should be noted that compared to the United States, European countries have a proportionately higher number of bicyclists. It should also be noted that smaller, single-lane, low-speed roundabouts are likely safer for bicyclists than larger, multilane roundabouts. Several recommended approaches for improving bicycle safety at roundabouts include (Robinson et al., 2000): Avoid bicycle lanes on the outer edge of the circulatory roadway. A 1992 German study focusing on bicycle safety at urban intersections found that including bike lanes or crosswalks on the outside of a "circular intersection" actually created more safety risk in an already dangerous environment than when bicycles simply shared the roadway with motor vehicles. It should be noted, however, that the intersections studied did lack some of the safety attributes of modern roundabouts (Schnll et al., 1992). Even when bicycle lanes are provided on the outside edge of a roundabout, preliminary results of a Danish study suggest that 60 percent of bicyclists do not even use the bicycle lane (Herrstedt et al., 1993). It should be noted that the MUTCD states that bicycle lanes shall not be provided on the circular roadway of a roundabout intersection. On single lane roundabouts where vehicular traffic volumes are low and operating speeds are lower, allow bicyclists to mix with vehicular traffic without any separate facility outside the circulatory roadway. Speed is a fundamental risk factor in the safety of bicyclists. Design treatments that slow traffic such as tightening entry curvature and entry width, and radial alignment of the legs of a roundabout should improve bicycle safety. The necessity of a safe entry is illustrated by a 1986 study that found 86 percent of collisions involving bicycles and motor vehicles occurred between circulating bicyclists and motor vehicles entering the roundabout (Layfield and Maycock, 1986). Robinson et al. (2000) indicate that commuter bicyclist speeds can range from 19 to 24 km/h (12 to 15 mph) and designs that constrain the speeds of motor vehicles to similar values will minimize the relative speeds and improve safety. EXHIBIT V-32 Strategy Attributes for Accommodating Bicyclists through Roundabouts (T) Attribute Description Technical Attributes Target This strategy should be considered at all roundabouts where bicyclists may be expected. Expected The use of modern day roundabouts is still in its infancy in the United States. As a result, Effectiveness the few safety evaluations of these facilities that have been conducted have focused on the safety impacts to motor vehicles, and for the most part, the negative impacts that roundabouts have on bicyclists have been identified but not studied. Thus, no accident studies have been conducted that estimate the safety benefit to bicyclists of implementing the recommended approaches to improving bicycle safety at roundabouts. However, these recommended approaches are in European policies where roundabouts have a V-45

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-32 (Continued) Strategy Attributes for Accommodating Bicyclists through Roundabouts (T) Attribute Description Technical Attributes longer history of use so it is reasonable to expect that implementing these recommended approaches will improve bicycle safety at roundabouts in the United States. Keys to Success Because roundabouts are still a relatively new intersection treatment in the United States, new roundabouts are being constructed around the country. The key to success is to design these new roundabouts to accommodate bicyclists initially, rather than to modify the design at a later date to accommodate bicycle travel. Also, all traffic control devices should be in compliance with the MUTCD. Potential Difficulties It is difficult to ignore the safety benefits to motor vehicles that have been reported in the various safety evaluations. Persaud et al. (2001) reported reductions of 40 percent for all crash severities combined and 80 percent for all injury crashes, and reductions in the numbers of fatal and incapacitating injury crashes were estimated to be about 90 percent. Agencies may be willing to overlook the safety disbenefits to bicyclists in exchange for the safety benefits to motorists. Appropriate Measures A key process measure is the number of roundabouts under the jurisdiction of the and Data highway agency. Crash frequency and severity, by type, are key safety effectiveness measures, and location data are important to diagnosis a safety problem (e.g., did the crash occur on the approach to the roundabout, at the entry, or within the circulatory roadway). Crash frequency and severity data are needed. Bicycle and motor vehicle volume data are needed to represent exposure. Speed is also a fundamental risk factor in the safety of bicyclists, especially at roundabouts, so it is an important safety measure to collect vehicular speed data on approach and entry, as well as within the circulatory roadway. Associated Needs None identified. Organizational and Institutional Attributes Organizational, Related to the potential difficulties, highway agencies should establish a policy to Institutional and consider bicyclists during the design of every roundabout. Policy Issues Issues Affecting Because roundabouts are currently being constructed, these recommended approaches Implementation Time to improving bicycle safety at roundabouts could be considered during the design process and should have minimal impact on completing the final design of a roundabout. Costs Involved Costs for accommodating bicyclists at roundabouts are minimal in most cases. Training and Other Training regarding use of this strategy should be provided in highway agency courses Personnel Needs covering the use and design of roundabouts. Legislative Needs None identified. Other Key Attributes None identified. V-46

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SECTION V--DESCRIPTION OF STRATEGIES Strategy A8: Provide an Overpass or Underpass (T) General Description At path/roadway intersections, an overpass or underpass allows for uninterrupted flow for bicyclists and completely eliminates exposure to vehicular traffic. These grade- separated crossings can improve safety and are desirable at some locations. However, because grade-separated crossings can be quite expensive, may be considered unattractive, may become sites of crime or vandalism, and may even decrease safety if not appropriately located and designed, these types of facilities are primarily used as measures of last resort (AASHTO, 2004; Zegeer et al., 2004). The AASHTO Bicycle Guide (1999) provides guidance on the design of overpasses and underpasses. This strategy is related to Strategy 9.1 A5-- Install Overpasses/Underpasses in NCHRP Report 500, Volume 10: Guide for Reducing Collisions Involving Pedestrians. EXHIBIT V-33 Strategy Attributes for Providing an Overpass or Underpass (T) Attribute Description Technical Attributes Target This strategy primarily focuses on path/roadway intersections, particularly at intersections of freeways or other high-speed, high-volume arterial streets. Expected The effectiveness of this strategy depends largely upon the likelihood that bicyclists will Effectiveness utilize the facility to cross the street, which is determined largely by convenience. If the grade-separated crossing is placed within a reasonable distance of the desired route/path of the bicyclists, it will likely be highly utilized. If bicyclists have to go out of their way to access the grade-separated crossing, it will be underutilized. One agency suggests that an overpass or underpass should be at least 600 ft from the nearest alternative "safe" crossing (Edwards and Kelcey, 2002). A safe crossing is defined as a location where a traffic control device stops vehicles to create adequate gaps to cross. Keys to Success One key to success is establishing a policy that may be used to determine the need for a grade-separated crossing. For example, Exhibit V-34 illustrates guidelines established by the Minnesota DOT to help determine the need for grade-separated crossings. Several other factors that should be considered in determining the need for grade separation include (Minnesota DOT, 1996): Traffic volume and traffic mix Motor vehicle operating speeds Number of lanes to be crossed (i.e., crossing distance) Sight distance Design bicyclist Approach grade Destinations Design of turning movements Primary path function V-47

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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-33 (Continued) Strategy Attributes for Providing an Overpass or Underpass (T) Attribute Description Technical Attributes Approaching path design Impact of bicycle traffic on vehicular traffic EXHIBIT V-34 Choice of Intersection Type (Minnesota DOT, 1996) Another key to success of grade-separated crossings is they must be well-designed. Several attributes of well-designed grade-separated crossings include (AASHTO, 2004): The facility is located where it is needed and will actually be used. Crossing structures are built with adequate widths. The design is accessible for all users (i.e., meets ADA requirements). Barriers/railings are provided to add an increased sense of safety. The facility is well-lit to provide an increased level of security. Potential Difficulties Potential difficulties include ensuring that bicyclists will utilize the facility. Also nearby residents may find the structure "ugly" and may complain about loss of privacy (Zegeer et al., 2004). Grade-separated structures often require a considerable amount of right of way. Underpasses can have drainage and associated debris problems if not properly designed and maintained. Crime, vandalism, and graffiti can also cause problems. Appropriate Measures A key process measure is the number of grade-separated crossings at path/roadway and Data intersections. V-48