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SECTION V--DESCRIPTION OF STRATEGIES Several of the companion guides provide detailed information on speed enforcement programs intended to reduce motor vehicle speeds. The reader is referred to these guides for more detailed information on implementing speed enforcement. In particular, the reader is directed to the following objectives and strategies in the respective guides: · NCHRP Report 500, Volume 1: A Guide for Addressing Aggressive-Driving Collisions Objective 4.1 A--Deter aggressive driving in specific populations, including those with a history of such behavior, and at specific locations Strategy 4.1 A1--Target enforcement · NCHRP Report 500, Volume 5: A Guide for Addressing Unsignalized Intersection Collisions Objective 17.1 H--Reduce operating speeds on specific intersection approaches Strategy 17.1 H1--Provide targeted speed enforcement · NCHRP Report 500, Volume #TBA: A Guide for Reducing Speeding-Related Crashes on High- Speed Roadways Objective C--Improve efficiency and effectiveness of speed enforcement efforts Strategy C1--Use targeted conventional speed enforcement programs at locations known to have speeding-related crashes Objective D--Reduce Bicycle Crashes at Midblock Crossings Strategy D1: Improve Driveway Intersections (T) Driveway improvements are intended to modify the EXHIBIT V-55 intersection of driveways and roadways to minimize Unsafe Driveway Intersections may Lengthen Conflict Areas Between Bicyclists potential conflicts between bicyclists and motor and Motor Vehicles (Dan Burden, vehicles. The design of connections to the street network http://www.pedbikeimages.org) has a considerable impact on bicyclist safety and access because a significant portion of bicycle/motor vehicle crashes (approximately 20 percent) occur when either bicyclists or motorists ride or drive out from a driveway without properly yielding to oncoming traffic. Every driveway connection is a potential conflict point for motorists, bicyclists, and pedestrians and should be designed to minimize unsafe conflicts. Examples of driveway intersection improvements include: · Tighter turn radii at driveways that slow vehicle speeds. Curb cuts should have sufficient flare, however, for bicyclists to complete turns into the driveway or into the nearest lane without "swinging wide" into the adjacent lane. · On streets with sidewalks, the walkway should continue at grade across the driveway to provide for clear pedestrian movement and make it clear to motorists and bicyclists that pedestrians have the right-of-way. V-76
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SECTION V--DESCRIPTION OF STRATEGIES · Paved driveway approach aprons may be EXHIBIT V-56 better suited for intersections with Paved Driveway Aprons Help Keep Gravel from the Bikeway unpaved streets and driveways so that (Portland, http://www.trans.ci.portland.or.us/ gravel and debris can be contained and designreferences/bicycle/appenda1.htm) prevented from accumulating in the bikeways, where it can lead to unsafe riding conditions at the driveway intersection. Although 4.6 m (15 ft) is a typical minimum length for the paved apron, to better reduce transfer of gravel and debris from the unpaved portion into the bicycle lane, longer paved aprons should be considered. Driveway aprons should also not have deep "lips" or grooves that may disrupt bicycle tires. · Driveway right-of-ways should also be kept cleared of foliage, signs, and other objects that obscure visibility. · Pavement markings may improve conditions for bicyclists at driveway intersections; although skip-striping is typically intended to provide information to motorists about an approaching intersection with a right-turn lane, it might also be considered as a means of informing bicyclists that drivers might turn into the driveway. Because every driveway intersection is a potential conflict location, reducing the number of driveways through driveway consolidation or other measures should also be considered, particularly for arterials and collector roads. See Strategy D2--Implement Access Management for more discussion. EXHIBIT V-57 Strategy Attributes for Improving Driveway Intersections (T) Attribute Description Technical Attributes Targets Driveway improvements target both bicyclists and motorists. Bicyclists benefit from safer mid-block driveway intersections, and motorists are encouraged to operate more safely as a result of improvements. Expected Approximately 20 percent of bicycle/motor vehicle crashes occur at driveway locations. Effectiveness This strategy is intended to improve conditions for bicyclists at driveway locations, and result in reduced bicyclist-involved crashes at those locations. This strategy is expected to result in the following types of improvements: · Provide good visibility for motorists and bicyclists accessing the roadway. · Slow motor vehicles entering / exiting the roadway and establish pedestrian right-of-way. V-77
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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-57 (Continued) Strategy Attributes for Improving Driveway Intersections (T) Attribute Description Technical Attributes · Reduce the chances of a bicycle-only fall or turning error when bicycles enter or leave the roadway. Driveway improvements also may improve conditions for pedestrians. Keys to Success It is best to properly design and consolidate driveways at the outset. Local regulations can require appropriate driveway design when driveways are repaired or modified, or when new driveways are built. Where there is a parking and/or bicycle lane, consideration should be given to designing curb radii tighter than modern guides recommend (e.g., older cities in the Northeast and in Europe frequently have radii of 0.6 to 1.5 m [2 to 5 ft]). More typically, in new construction, the appropriate turning radius is about 4.6 m (15 ft) and about 7.6 m (25 ft) for arterial streets with a substantial volume of turning buses and/or trucks. Tighter turning radii are particularly important where streets intersect at a skew. While the corner characterized by an acute angle may require a slightly larger radius to accommodate the turning movements, the corner with an obtuse angle should be kept very tight, to prevent high-speed turns. It is important to make sure that public maintenance vehicles, school buses, and emergency vehicles are accommodated. Potential Difficulties Several driveway designs may cause safety and access problems for pedestrians, including excessively wide or sloped driveways, driveways with large turning radii, multiple adjacent driveways, driveways that are not well defined, and driveways where motorist attention is focused on finding a gap in congested traffic. Local landscape ordinances and other driveway guidelines may be needed to establish clear zones for driveway rights-of-way and maintain roadway surfaces. Along corridors, driveway consolidation creates the need for u-turns, which can be hazardous along roadways with high speeds or ADTs. Large trucks and buses may ride over the curb at intersections with tight radii, creating a danger for pedestrians who are waiting to cross. Driveways without a level sidewalk landing may not comply with ADA pedestrian standards. See Designing for Pedestrians with Disabilities, http://www.walkinginfo. org/de/index.htm. Appropriate Measures A key process measure is the number of driveways that receive improvements. and Data Performance measures include the number of crashes involving bicyclists at driveways, and bicycle and motor vehicle volume data are needed to represent exposure. Associated Needs None identified. V-78
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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-57 (Continued) Strategy Attributes for Improving Driveway Intersections (T) Attribute Description Organizational and Institutional Attributes Organizational, Agencies may need to develop new or revised driveway design, construction, and Institutional, and access management policies. Policy Issues Issues Affecting Implementation time may be affected by the amount of public involvement and Implementation Time controversy surrounding the proposed program. This can occur during the planning, design, and funding acquisition processes. Costs Involved No additional costs are incurred when incorporated into original plan and construction. Costs for retrofitting changes vary depending on existing conditions and scope of work. For example, construction costs for reconstructing a tighter turning radius are approximately $2,000 to $20,000 per corner, depending on site conditions (e.g., drainage and utilities may need to be relocated). Training and Other Because sidewalks also cross many driveways, training on ADA requirements may Personnel Needs be needed for anyone involved in the design, construction, or maintenance of driveway areas. Legislative Needs Changes to driveway requirements may require updates to local development and construction regulations. Other Key Attributes None identified. Strategy D2: Implement Access Management (T) Managing the number, spacing, access, directional flow, and other aspects of driveway connections protects those traveling along the corridor from conflicts with those entering or leaving the corridor. Every driveway connection is a potential conflict point among motorists, bicyclists, and pedestrians. Access management strategies such as providing raised/non-traversable medians and limiting driveway access may be useful in promoting safe bicycle travel, particularly on arterial or major collector streets, since they help reduce the number of potential conflict points. The principles of access management incorporate providing specialized roadways appropriate to their intended use. The trade-off is between providing direct access and promoting through movement. For example, the main purpose of freeways and arterials is to move through traffic, and access should be restricted to necessary interchanges. Local streets should generally serve all destinations, and access should not be limited. There are exceptions, however, if management is needed to reduce non-local traffic. Access management includes such measures as: · limiting the number of driveways (or establishing minimum spacing between driveways), V-79
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SECTION V--DESCRIPTION OF STRATEGIES · providing for right-in, right-out only movements, · locating signals to favor through movements, · restricting turns at certain intersections, and · using non-traversable medians to manage left- and U-turn movements. For more information: · The Transportation Research Board (TRB) Committee on Access Management identifies 10 principles or strategies of access management altogether, along with the rationale and elements of a comprehensive program (see http://www. accessmanagement.gov/). · TRB also published the Access Management Manual in 2003 that provides comprehensive descriptions of access management principles, techniques and effects, and rationale and steps toward developing an access management program and policies. · Oregon DOT provides extensive guidance to local communities for access management as it relates to bicycle and pedestrian planning and facility development (see http://www. odot.state.or.us/techserv/bikewalk/planimag/backgrnd.htm). EXHIBIT V-58 Effective Access Management Reduces the Number of Conflict Points (Oregon DOT, http://www.odot.state.or.us/techserv/bikewalk/planimag/backgrnd.htm) V-80
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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-59 Strategy Attributes for Implementing Access Management (T) Attribute Description Technical Attributes Targets This strategy targets bicyclists who utilize multi-lane arterial or collector roadways and left-turning motorists on those roads. Expected By limiting and consolidating driveways, by providing raised or landscaped medians, or Effectiveness by creating frontage roads, bicyclists and pedestrians benefit in several ways: · The number of conflict points is reduced; this is best achieved by replacing a center- turn lane with a raised median (left turns account for a high number of crashes with bicyclists and pedestrians). · Motor vehicles are redirected to intersections with appropriate control devices or appropriate assignment of right-of-way. · Pedestrian crossing opportunities are enhanced with an accessible raised median and fewer conflicts with turning cars. · Accommodating people with disabilities is easier, as the need for special treatments at driveways is reduced. · Improved traffic flow may reduce the need for road-widening, allowing part of the right-of-way to be recaptured for bicyclists, pedestrians, and other users. Benefits of this strategy include smoother vehicle flow, reduced delay, and fewer crashes (Gluck et al., 1999; Demosthenes, 2003). Effective access management planning can also reduce total roadway facility costs by reducing the number of driveways and intersections. Demosthenes (2003) found that access locations (driveways and intersections) account for more than 60 percent of vehicular crashes in urban areas, so incorporating access management strategies can significantly reduce urban crash rates. Keys to Success It is difficult to retroactively reduce, consolidate or eliminate existing accesses. Policies that properly control access should be adopted so that agencies can proactively work to improve safety for bicyclists and motorists. A PI&E program should be developed and implemented to educate bicyclists and motorists of the intended purpose of the access management changes, as well as alert them to upcoming changes in traffic patterns. A test period may be helpful to identify and make adjustments to potential problems for affected properties. Potential Difficulties Limiting the number of street connections may have a negative impact on non- motorized mobility, especially for pedestrian crossings: · Providing for free-flow of traffic by reducing connections may result in increased travel speeds and volumes. · Eliminating local street crossings eliminates pedestrian crossing opportunities, reduces pedestrian and bicycle travel choices, and may increase out-of-direction travel. · Reduced access to businesses may require out-of-direction travel, discouraging walking and bicycle trips. V-81
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SECTION V--DESCRIPTION OF STRATEGIES EXHIBIT V-59 (Continued) Strategy Attributes for Implementing Access Management (T) Attribute Description Technical Attributes · Placing concrete barriers down the middle of the road (rather than a raised or landscaped median) effectively prohibits pedestrian crossings. · Improperly designed raised medians act as barriers: pedestrians should be able to see to the other side of the street (vegetation should not decrease visibility) and curbs should be no more than standard height. Access management that reduces traffic conflict and traffic speeds, or reduces total vehicle travel, is expected to result in increased traffic safety. By contrast, access management that simply increases arterial traffic speeds can increase automobile use, and may discourage nonmotorized transportation. Development of an access management program should include awareness of this difference and focus on activities that reduce traffic conflict and speed. There may be costs associated with specific designs and changes to driveway access. It can favor economic development in some locations over others, which imposes costs on some businesses and property owners, and benefits others. Appropriate Measures Performance measures include the number of crashes involving bicyclists at mid-block and Data locations, and bicycle and motor vehicle volume data are needed to represent exposure. Associated Needs Access management policies need to be coordinated with land use regulations. These policies may easily conflict with each other unless all agency stakeholders are involved. Development of access management requires consistency so that all aspects of motorized transportation, nonmotorized transportation, and land use management/development support the desired outcomes. Organizational and Institutional Attributes Organizational, Agencies that implement access management changes should involve all potentially Institutional, and affected parties early in the planning process. Agencies may need to develop new or Policy Issues revised policies regarding access management, or support their governing bodies in the development of new or revised policies. Public hearings may be required if driveway access will be restricted or changed. Issues Affecting It may take significant time to implement this strategy. Studies should be conducted to Implementation Time determine whether the strategy is appropriate and to identify the most appropriate treatment or countermeasure to address the existing environment. Costs Involved If included in initial design and construction, access management measures might raise or decrease costs compared to other designs. Cost of retrofit measures would depend on the type and extent. For example, adding a raised median is estimated to cost $15,000 to $30,000 per 30 m (100 ft). Prohibiting left turns with diverters may cost from $15,000 to $45,000 each. Access management activities can have a number of equity impacts. Changing vehicle access and development patterns can harm some businesses and property owners, while benefiting others. Property owners sometimes receive compensation for lost access. V-82