Minnesota Department of Transportation

511 Travel Info

Research & Innovation

Comparative analysis of grade-separated pedestrian infrastructure and at-grade treatments

Need Statement 715


Across Minnesota, many smaller communities are bisected by MnDOT roadways or similar arterials creating significant barriers for pedestrians and bicyclist to access their schools, grocery stores, work, or other community destinations. As MnDOT works to increase walking and biking mode shift to align with ambitious goals in the Statewide Multimodal Transportation Plan (SMTP) and reduce transportation emissions for climate change there is a significant need to identify affordable, easier to implement solutions.

Guidance on deciding when/how to implement grade separated crossings and what to do at at-grade crossings if a grade-separated crossing is not feasible will help MnDOT and local agencies better address pedestrian and bicyclist safety.


Communities typically ask for bridges, underpasses, or tunnels. However, these infrastructure changes are costly and often create more issues (snow removal, personal safety, etc) than they solve for communities while being too costly to implement for most communities.

This research seeks to address the following questions:

  • Are there roadway characteristics that could be considered a threshold for implementation of grade-separated crossings? (E.g., AADT/speed/number of lanes/functional classification)
  • Are there priority destinations for pedestrians and bicyclists like schools, employment centers, or grocery stores that create a greater need for these larger engineering treatments?
  • Are there locations where making changes to the at-grade crossing environment would be more cost effective?
  • What are decision-making factors in selecting a bridge/overpass versus an undercrossing? Can undercrossings be designed to be more appealing?
  • On corridors where a grade-separated crossing is the ideal treatment, how should the best location for the bridge(s) or undercrossing(s) be determined?

Strategic priorities

  • Asset Management: Adding new bridges, underpasses, or tunnels to the system will inevitably increase the overall maintenance and repair cost burden. A greater understanding on the value added to the network from infrastructure improvements would be helpful for long term decision-making.
  • Safety: Improve pedestrian and bicyclist access to community destinations where MnDOT or similar arterial roadways bisect communities and present safety concerns.
  • Climate Change & Environment: Increase walking and biking mode shift to reduce transportation emissions.

Expected outcomes

  • New or improved technical standard, plan, or specification
  • New or improved manual, handbook, guidelines, or training
  • New or improved business practices, procedure, or process
  • New or improved tool or equipment
  • New or improved decision support tool, simulation, or model/algorithm (software)

Expected benefits

  • Decrease Engineering/Administrative Costs:   Reduced planning/design costs
  • Environmental Aspects: Air Pollution
  • Lifecycle: Reduce maintenance cost
  • Operations and Maintenance Savings: Reduced labor
  • Safety: Reduction of crash frequency

Technical advisory panel

  • tbd