Geometric Design of Low-Speed Urban Streets

A research effort is progressing to develop a rational process for designing roadway geometric elements on low-speed urban streets and using a “target”operating speed as the preselected design speed. The goal is to provide geometric street designs that reflect the in situ operating environment (form to follow function). Such an approach produces geometric conditions that result in operating speeds that are consistent with driver expectations and commensurate with the function and purpose of the roadway. The data collection methodology being used to develop a speed-prediction model between operating speed and roadway geometry, roadside features, land use, and traffic engineering considerations is also described. A comparison of design speed and operating speed for one study site is provided as an example of anticipated results.