About the research
Right-turn-on-red (RTOR) has been used in the US for several decades, beginning in California as early as 1937, before being adopted by most states during the energy crisis of the 1970s. In current practice, allowance of RTOR is the default assumption by most drivers, with local prohibitions noted by use of the NO TURN ON RED sign, and area-wide prohibitions in certain local jurisdictions (such as in New York City).
There are several significant gaps in tools available to practitioners regarding RTOR, which are present in current guidance documents. The most fundamental of these is guidance on whether RTOR should be permitted or prohibited at a location. The Manual on Uniform Traffic Control Devices (MUTCD) lists six conditions where a NO TURN ON RED sign should be used.
Some of these conditions, such as sight distance, are unambiguous, but others such as geometric and operational characteristics are more open to judgment. Other guidance documents have included their own statements regarding RTOR, but these also stop short of offering a unified method for determining whether to prohibit RTOR.
The research team offers a vision of execution that includes three key elements that they believe can result in outcomes that are highly transferable, versatile, and which will lead to greatly accelerated implementation into practice. This includes approaches to data collection, modeling, and implementation that each provide novel contributions to the analysis of RTOR volumes, and perhaps to capacity analysis more generally.