Road diet informational guide.

2014PDFTech ReportFHWA-SA-14-028Contract No. DTFH61-10-D-00024, Task Order No. T-12-004Three lane highwaysFour lane highwaysTwo way left turn lanesLeft turn lanesHighway engineeringHighway safetyTraffic safetyRoad diet, Four-lane highways, Undivided highways, Three-lane highways, Two-way-leftturn-lane, Cross section, Safety, Operations,Reconfiguration, QueuingUnited StatesUnited States. Federal Highway Administration. Office of SafetyKnapp, KeithChandler, BrianAtkinson, JenniferWelch, ThomasRigdon, HeatherRetting, RichardMeekins,StaceyWidstrand, EricPorter, R.J.LeidosUnited States. Federal Highway Administration. Office of SafetyFederal Highway AdministrationA classic Road Diet converts an existing four-lane undivided roadway segment to a three-lane segment consisting of twothrough lanes and a center two-way left turn lane (TWLTL). A Road Diet improves safety by including a protected left-turn lanefor mid-block left-turning motorists, reducing crossing distance for pedestrians, and reducing travel speeds that decrease crashseverity. Additionally, the Road Diet provides an opportunity to allocate excess roadway width to other purposes, includingbicycle lanes, on-street parking, or transit stops. This Informational Guide includes safety, operational, and quality of life considerationsfrom research and practice, and guides readers through the decision-making process to determine if Road Diets area good fit for a certain corridor. It also provides design guidance and encourages post-implementation evaluation