Permanent street design changes can take years and involve significant resources to enact. Adaptive design strategies are temporary right-of-way improvements that provide quick, low-cost solutions for reallocating street space to address an opportunity or to mitigate a concern. Use of adaptive design strategies has one overarching aim: to reconfigure space within the public right-of-way to respond to the needs of an evolving community of users. Adaptive design strategies can take on a variety of functions. These include experimentation, piloting and demonstrating new designs, addressing safety issues, and increasing public space. Above all, adaptive measures are meant to provide responsiveness and flexibility. Adaptive design strategies allow transportation agencies to address issues in the near term. They provide practical amenities or safety improvements where they are needed most until permanent or larger scale improvements can be constructed. By definition, adaptive design strategies should be relatively quick and cost effective, with little to no impact on material integrity or utilities where sited.
The duration of an adaptive measure varies depending on its location, function, and the resources available to maintain or replace it. An adaptive measure could be installed for hours, days, seasons, or years depending on the context. As a general rule, however, adaptive design strategies should either be removed or made permanent within a 3- to 5-year timeframe.
Regardless of the duration, monitoring and evaluating the performance of adaptive treatments is vital to understanding their performance, effectiveness, and the decision on whether to return a street to its previous condition or to construct permanent improvements. By evaluating usage of an adaptive treatment, agencies can quickly change its configuration or alter plans for permanent infrastructure to more effectively suit the community’s needs.
"Paint and post" separated bike lane (photo courtesy: City of Phoenix).
"Paint and post" bulb out.
Temporary Pop Up Demonstration, 3rd Street, Phoenix, AZ
Separated bicycle lanes have been implemented in many cases as low-cost retrofit projects (e.g. using flexible delineators and pavement markings within the existing right-of-way). More permanent forms of separation, such as curb-protected bicycle lanes, cost more and are less flexible once implemented. A phased implementation approach, where “pilot” projects transition to permanent protected bicycle lanes, may solve both of these problems. This would be done by implementing the facility slowly and troubleshooting before permanent materials and high costs are necessary.
Example of Bicycle Lane Evolution.
Low-Cost Paint and Post Separated Bike Lane (2nd Ave Seattle).
Separated bike lane with more permanent curb and planters (2nd Ave Seattle).