WSDOT transportation engineers and planners are working with local agencies, FHWA and others to improve, connect, or re-connect grid systems because of a growing body of research that shows cities with
transportation systems often have low per capita emissions, less traffic congestion, and are more walkable.
Complete grid systems in and around congested urban areas, especially where state highways intersect with busy surface streets, may help state highway infrastructure to maintain acceptable levels of service longer, reduce maintenance costs, and improve safety.
Contact: Community Design Assistance for help finding innovative solutions to your community's transportation challenges.
Designing a Connected Transportation System
A growing body of research supports these basic practices for designing a connected transportation system.
- Maintain a block length of 300-600 feet or provide mid-block pedestrian crossings.
- Maintain road connections and loop roads vs. dead-end and cul-de-sac streets in street layouts for new development.
- Maintain road, pedestrian and bicycle connections with adjoining parcels/property.
- Relate street design to the land uses they serve.
- Integrate new roads with existing streets and maintain bicycle and pedestrian connections.
- Include convenient pedestrian access in site and street designs.
- Minimize curb cuts and incorporate well marked, signed and/or signalized pedestrian crossings in higher traffic areas.
- Incorporate traffic calming.
- Provide off-street paths connections for bicyclists and pedestrians.
- Keep vehicle speeds lower than 35 mph.
- Place buildings to reduce walking distances (minimum lot frontage and maximum building spacing)
- Consider service alleys to provide motor vehicle access behind buildings and parking areas.
Research and Resources