A road diet is a conversion of usually a four-lane roadway to a three-lane road made up of two through lanes and a center-two-way-left-turn -lane. Drivers can use the dedicated turn lane to safely turn and move out of the traffic flow, so they’re not holding up drivers behind them.
With a road diet, left turns will only cross one lane of traffic instead of two. The reduction of lanes allows the roadway cross section to be reallocated for other uses such as bike lanes, pedestrian refuge islands, transit stops, or parking.
The science behind road diets
Studies conducted by the Federal Highway Administration have found several benefits of road diet installation:
- An overall crash reduction of 19 to 47 percent;
- Reduction of rear-end and left-turn crashes through the use of a dedicated left-turn lane;
- Fewer lanes for pedestrians to cross and an opportunity to install pedestrian refuge islands; and,
- The opportunity to install bicycle lanes when the cross-section width is reallocated.
Why install road diets?
- Reduces traffic speed
- Reduces rear end and head on collision crashes
- Accommodates bike and enhanced pedestrian safety
- Creates better connectivity for pedestrians and bicyclists
- Dedicated turn lanes ease anxiety for drivers
See below for a brief video from ITRE on road diets.