What’s in a corridor? Perhaps a better question is, what’s not? The National Cooperative Highway Research Project just released a NCHRP Report 661: A Guidebook for Corridor-Based Statewide Transportation Planning that provides a template for corridor planning to help states understand the connections between transportation decisions and issues like mobility, economic development, communities and the environment. They claim that statewide corridor planning (SWCP) is a more useful approach than system-wide orproject-based processes, and offer technical guidance and examples.
Why is SWCP better than traditional methods? In a nutshell, it emphasizes system preservation for the most important corridors, modes and facilities in the state or region. It can be easier to examine trade-offs among different modes, and enables more detailed project information like cost estimates. It also allows a more thorough exploration of non-transportation solutions (like land use and zoning) to transportation challenges.
They recommend the following five-step process:
- Establish your organizing principles and institutional structure, including participation of non-metropolitan officials. Local officials’ input can be valuable for the success of statewide transportation plans.
- Establish a corridor network, viewed from a multimodal perspective. With system preservation as the goal, an SWCP process emphasizes coordinating modal strategies rather than addressing each mode separately.
- Identify study corridors, preferably a mixture of inter-city and metropolitan routes. A GIS can be a useful tool for scoring corridors based on preferred criteria, and it is a good idea to make a statewide database to collect data on performance and conditions over time.
- Conduct corridor studies. This process may be detailed or brief depending on your needs. You should broadly define the “problem” to be solved by the project—this may include protecting environmentally sensitive areas, maybe social justice goals?
- Create a statewide investment program and system management strategy. Consider both technical data and public input, and any factors of statewide or regional importance such as geographic equity, economic development needs, and other issues. Corridor studies can make recommendations beyond transportation infrastructure (smart growth, anyone?) so it pays to think broadly.
Adequate data is necessary for an SWCP approach. This includes traffic volumes, level of service, crash data, pavement conditions, adequacy ratings, and travel times for the corridors. You can also use data specific to transit (passenger volumes, trip frequency, mode, vehicle capacity) or freight (freight volumes by commodity, operator/driver regulations, delivery schedules, weight restrictions, off-loading transfer times). While states use both custom and government-sponsored tools for their analysis, it’s worth noting that none of the tools currently used deal with intermodal issues. This looks like a job for corridor-level planning!
What other goals might a corridor-based approach help accomplish? What kinds of data would be needed to do this? Leave a comment and tell us your ideas!