Although agencies have not yet fully implemented Performance-Based Practical Design, these case studies illustrate some of its key attributes.
State DOT Examples
Minnesota: Access Planning
- One-Page Overview of Minnesota Case Study (.pdf, 0.5 mb)
- Full Case Study: Minnesota Highway 10 Access Planning Study (.pdf, 1 mb)
This 2016 case study illustrates how the Minnesota Department of Transportation utilized quantitative performance analysis to develop project alternatives that would attain most of the safety and operational benefits of a freeway at significantly lower cost.
Arizona: Safety Improvement Evaluation
- One-Page Overview of Arizona Case Study (.pdf, 0.5 mb)
- Full Case Study: Arizona SR 264 Burnside Junction to Summit (.pdf, 0.5 mb)
This 2015 case study illustrates how the Arizona Department of Transportation Traffic Safety Section took a systemic approach to reviewing two-lane rural highways with a high potential for run-off-roadway crashes in order to identify and prioritize treatments to improve safety.
Kansas: Design to Budget
- One-Page Overview of Kansas Case Study (.pdf, 0.5 mb)
- Full Case Study: K-177 Modernization Project (.pdf, 1 mb)
This 2014 case study highlights a specific project for which the Kansas Department of Transportation conducted extensive modeling of current and projected operations and safety, which allowed them to select a project scope that achieves the performance objectives of a rural corridor modernization project within given budget constraints.
Low-Cost Pedestrian and Bicyclist Safety and Mobility Improvements
Pedestrian and bicyclist improvements can be a natural part of Performance Based Practical Design (PBPD) considerations on many projects. The following case studies illustrate that pedestrian and bicyclist safety and operational performance may be enhanced both at the project level and at a larger, system-wide scale. Incorporating performance analysis provides these projects a better understanding of associated safety and mobility impacts.
- Soapstone Drive Road Diet: This case study of a project in Reston, Virginia illustrates a cost-effective improvement for bicyclists that took advantage of the community's existing paving schedule and resulted in a large decrease in crashes involving bicyclists.
- Exclusive Pedestrian Phasing in Beverly Hills: This case study shows how a low-cost pedestrian enhancement can be implemented throughout a network to improve safety. Performance analysis allowed the City of Beverly Hills, California Engineering Department to investigate trade-offs and to maintain the enhancements only in those areas where benefits outweighed the costs.
- Nickerson Street Road Diet: This case study illustrates how a single project can address both bicyclist and pedestrian safety concerns at a relatively low cost. This Seattle, Washington project also included a rigorous before-and-after performance analysis, tracking both vehicle speeds and crash incidence rates.
- Arkansas (Metroplan MPO, Little Rock region): Public survey of localized congestion problems
- Austin, Texas: Restriping of two lanes to "reclaim" a third lane
- Arvada, Colorado: A grade-separation project to eliminate recurring problems caused by a railroad crossing
- Danbury, Connecticut: Restriping an interchange instead of rebuilding
- Madison, Wisconsin: Ramp meters as a countermeasure to delays and crashes
- Manchester, New Hampshire: Expedited improvement of a congested exit ramp as part of long-term phased construction
- Minneapolis-St. Paul, Minnesota: A study to determine effectiveness of ramp meters
- Pittsburgh, Pennsylvania: Conversion of a freeway shoulder into an acceleration lane at former chokepoint at top of ramp entrance
- Renton, Washington: Use of a freeway shoulder to maintain lane congruency and eliminate a lane drop chokepoint.
- Saginaw County, Michigan: Replacement of tight diamond ramp intersections with roundabouts as countermeasure to insufficient signalized intersections
- Washington DOT: Description of Washington State's 3-tiered "Moving Washington" congestion relief plan