Interchanges are a point of transition for vehicles travelling between streets (where vulnerable road user safety is a primary concern) and freeways (where pedestrians and cyclists are generally not permitted). They usually feature multiple high-volume, high-speed turning, merging and diverging movements, and pose significant challenges to the safety and comfort of vulnerable road users including people with disabilities, pedestrians, cyclists and other active transportation users.
At a network level, interchanges represent the main opportunities for pedestrians and cyclist to travel across freeways. The combination of forced routing and safety/comfort obstacles mean that interchanges can represent a major barrier to walking and cycling in urban areas, and can negatively impact municipal objectives for increasing active transportation.
There is limited guidance available from TAC or other jurisdictions to help planners and designers provide safe and comfortable facilities for walking and cycling at interchanges.
OBJECTIVES
The key objectives of this project are to:
- Provide descriptions of:
- The network-level impacts of freeway corridors on active transportation, and the importance of planning for freeway “permeability” for pedestrians and cyclists.
- The safety and operational impacts on active transportation users of all ages and abilities of conventional interchange designs (e.g. free-flow ramps with uncontrolled crossings, yield-to-vehicle conditions) and the resulting effects in terms of pedestrian and cyclist diversion, recognizing latent and suppressed AT demand.
- Document case studies of interchanges where:
- Active transportation desire lines are maintained for all ages and abilities.
- Conflict points are reduced or eliminated.
- People walking and cycling experience a high level of comfort.
- Collaboration between different orders of government has achieved positive outcomes.
- Synthesize established or emerging Canadian and international practices for:
- Planning and network-level approaches to minimizing conflict points for active transportation at interchanges, including dedicated active transportation overpasses/underpasses and alternative interchange layouts.
- Design approaches to accommodating active transportation at interchanges and the conditions under which each approach may be applicable. This may include:
- Geometric design measures (e.g. ramp configurations, curb radii, raised features, truck aprons)
- Traffic control measures (e.g. signs, signals, markings, AT or motor vehicle yielding requirements)
- Identify and evaluate possible future directions:
- Goals and principles for accommodating active transportation at interchanges, with a focus on urban contexts (including both developed and future settlement areas), while recognizing that rural interchanges require different considerations.
- Key opportunities and challenges facing the creation of urban interchanges that offer pedestrians and cyclists a level of safety, comfort, and accessibility equivalent to urban intersections, including for users of all ages and abilities and individuals with low vision or blindness, mobility impairments, or cognitive disabilities, while considering a range of factors including freeway operations, speed management, and geometric self-enforcement.
- Key opportunities and challenges facing the retrofitting of existing interchanges using a systematic approach that recognizes site constraints and potential trade-offs. This may include interim or staged interventions that improve safety and comfort where full reconstruction is not immediately feasible.
The main project tasks will include:
- A review of the relevant literature focusing on the Canadian context (both research and guidance), in addition to international beneficial practice guidance relevant to the Canadian context.
- A survey of key Canadian jurisdictions to identify approaches, methods, measured outcomes (e.g. impacts on collision rates and severity, pedestrian and cycling comfort and connectivity, and traffic conditions), and document case studies, including associated photos and drawings.
- Synthesis of current practice, guidance and lessons learned, identifying key themes and promising/proven measures as well as documenting limitations and potentially unfavourable practices. Where conflicts between guidance are identified, the synthesis should document how such conflicts are resolved in practice, including decision frameworks and considerations applied.
- An identification of gaps and opportunities to enhance current TAC guidance, in addition to conflicts between TAC and other guidance.
The main deliverables will include:
- A comprehensive report documenting the literature review and survey, case studies, synthesis of practice, and possible directions.
- A technical memorandum for the attention of relevant TAC committees that identifies gaps and opportunities related to TAC guidance, and suggests possible further work.