Road diet

A road in Davis, California, with four lanes curb to curb

The same road repainted after a road diet, with two through lanes plus bike lanes and a central left-turn lane

A road diet (also called a lane reduction, road rechannelization or road conversion) is a technique in transportation planning whereby the number and/or the width of travel lanes of the road is reduced. When properly implemented a crash benefit may be realized. Two separate studies showed a crash reduction rate of 19% and 47%. Upon reanalysis results also differ from the original Iowa study results (a 25 percent reduction) and from the original HSIS results (a 6 percent reduction). Combining both data sets results in a 29 percent reduction in total crashes.^[1]