4-1 4 Bus Facilities on Limited Access Highways In This Chapter: 4.1 General Planning and Design Considerations 4.2 Treatments 4.3 Operational Requirements 4.4 Protecting Future Needs 4.5 References Bus service on freeways and other limited-access highways continues to increase. That growth reflects the expansion of downtown and suburban oriented markets, the growth of HOV lanes, the development of bus-only roadways, and the emergence of bus rapid transit. Bus operation on freeways improves operating speeds and service reliability, especially where priority or exclu- sive facilities are provided. Providing separate facilities for buses and other high-occupancy vehicles (HOVs) can be a cost- effective means of improving person capacity within a corridor. The use of freeway rights-of- way usually results in lower land costs than for two separate facilities, reduces the displacement of businesses and residences, and lessens impact on neighborhoods. This chapter addresses bus facilities built within a controlled access highway environment, in- cluding special lane treatments for bus priorities, bus access facilities, and passenger transfer facilities within the freeway environment. The chapter begins by discussing general policy considerations such as eligibility, need and justification, and broad design guidelines. It then describes the various lane configurations and geometric guidelines for each type of treatment; provides guidelines for access into and out of busways, bus lanes, and HOV lanes; presents treatments for stations and stops; discusses operational requirements such as signing and enforcement; and addresses the desirability of protecting rights-of-way for the future. The focus is on bus-only facilities. However, since buses operate in HOV (or “managed”) lanes on many freeways, design requirements for these facilities are also included. c04.indd 1 27/11/13 4:57 PM 4-2 Guide for Geometric Design of Transit Facilities on Highways and Streets 4.1 GENERAL PLANNING AND DESIGN CONSIDERATIONS 4.1.1 Freeway Bus Service Types and Functional Requirements Transit operation on freeways includes a broad range of express, limited stop, and intercity services. Some services operate all day; others run only during peak periods. Some routes may operate non-stop, whereas others may make intermediate stops to serve intersecting local bus routes, park-and-ride facilities, or adjacent developments. A sound understanding of existing and potential bus routes, patterns of passenger demand, levels of rid- ership, and service delivery strategies is a prerequisite for developing transit infrastructure and design requirements. 4.1.2 Policy Context When buses operate with other traffic, the operating and enforcement decisions made by roadway engi- neers can influence the speed, reliability, and safety of transit services. A collaborative decision-making approach for transit (and carpool) operating, design, and enforcement policies is essential, especially on HOV, high-occupancy toll (HOT), and managed lane facilities that seek to maintain transit speed and reli- ability through congested freeway segments. Transit (and carpool) agencies often work closely with their respective state department of transporta- tion in each phase of facility development. Collaborative decisions also create a broader constituency for transit- and HOV-oriented policies that can provide broader support when transit-supportive freeway poli- cies are adopted. Policies can involve preservation of right-of-way for future improvements or integrated facility development within the roadway, often implemented as part of an overall road/transit improve- ment involving the same construction activities. 4.1.3 Selecting the Appropriate Facilities Transit vehicles operating in urban environments often are subject to delay caused by traffic congestion. Congestion results in longer travel times for passengers and may require transit agencies to add more buses to routes to maintain headways, which results in increased operating costs. (1) Preferential lane treatments for buses are implemented to reduce delays and improve reliability for transit operating in congested, mixed traffic. Fast and reliable services may also attract new riders, increase tran- sit capacity in a corridor, and improve the quality of transit services for passengers. According to the Transit Capacity and Quality of Service Manual (2nd Edition), bus preferential treat- ments generally can be defined as a range of techniques designed to improve transit vehicle travel speeds and improve overall system of efficiency. 15( ) Types of treatments include dedicated lanes operated as bus only or bus with other HOVs. These treatments may reduce travel time variability and improve schedule adherence for transit. The total person-delay (including passengers in both buses and private vehicles) should be considered when implementing a project to provide dedicated lanes for buses. Facilities should be cost-effective, and planners should consider both the long-term changes to mode split and the potential for attracting new users. Dedicated lanes are more acceptable to policy makers and the community when they do not create undue traffic disruptions to the general-purpose lanes. c04.indd 2 27/11/13 4:57 PM Chapter 4—Bus Facilities on Limited Access Highways 4-3 Buses operating along freeways may operate in bus-only roadways (busways) or in bus-only lanes or designated shoulders. Busways permit high speed, good adherence to schedule, and high visibility, which are desirable for bus rapid transit service. Bus-only lanes or shoulders along freeways improve bus service performance at a lower cost than a dedicated busway. HOV lanes and segregated bus roadways also improve bus speeds and reliability. Throughput is in- creased, particularly when dedicated lanes carry a large number of passengers. Barrier-separated HOV lanes usually require larger cross-sections than bus-only facilities. Sometimes, bus/HOV lanes function as elongated queue bypasses. Table 4-1 lists the types of preferential treatments for buses on limited ac- cess highways and provides the advantages and disadvantages of each type of treatment. 4.1.4 General Guidelines Two basic objectives underlie providing bus transit facilities on limited access highways: y Bus facilities should contribute to improved person throughput. y Bus facilities should be integrated into the corridor. Table 4-1. Types of Preferential Treatments for Buses on Limited Access Highways (1) Treatment Advantages Disadvantages Exclusive busways • Increase bus speed by reducing • Difficulty obtaining sufficient right-of- sources of delay way in existing or new corridor • Improve schedule reliability • Cost to construct • Increase transit identity and visibility Freeway bus lanes Same advantages as exclusive busway; • Adverse effects on traffic, if created however, benefits may not be as by eliminating an existing travel lane significant: • Cost to provide new capacity • Increase bus speed • Requires provisions for preferential • Improve schedule reliability access • May increase transit visibility Freeway HOV lanes • Improve operating speeds for transit • Adverse effects on traffic, if created users, carpool, and vanpool users by eliminating an existing travel lane • Improve schedule reliability • Cost to provide new capacity • Increase person movement capacity • Requires ongoing enforcement of roadway • May pose safety problems for vehicles entering and leaving the lanes unless physically separated Managed or express lanes • Improve transit operating speed • Requires a policy commitment to with preferential access for • Improve schedule reliability prioritizing transit as an objective of transit the managed lane operation Bus only or priority ramps • Maximizes the benefits of bus lanes • Cost to construct or HOV lanes by removing delays for • Requires ongoing enforcement access Queue bypass • Reduces delay for queues at ramp • Bus or HOV lane must be available meters or other locations • HOV preferential treatment requires ongoing enforcement c04.indd 3 27/11/13 4:57 PM 4-4 Guide for Geometric Design of Transit Facilities on Highways and Streets Additional key considerations include the following: y It is important to identify existing and anticipated congested areas. Generally, dedicated lanes should save at least 30 seconds per mile compared to travel in general purpose lanes. y It is not feasible to remove general purpose travel lanes in the heavy direction of travel for use by tran- sit (and HOVs). Priority facilities should be implemented through added lanes. y Standardization of freeway entrance and exit points to the right of the through traffic makes the use of median priority lanes feasible. y Metering of freeway ramps with bus (or HOV) bypass lanes can improve mainline freeway flow and reduce delays to buses/HOVs. y Radial freeways in urban areas that exceed one million population (especially two million) are good candidates for providing reservation for transit (or HOV) either within the median or alongside major roadway facilities. y Where bus rapid transit service is planned along freeways, building stations along the dedicated lanes can improve the speed, reliability, identity, and passenger attractiveness of the service. These are com- monly referred to as on-line or in-line stations. y Where right-of-way is limited, bus use of shoulders should be considered for congested highway facilities. Tables 4-2 and 4-3 provide some general design guidelines for transit lanes on limited access