A road diet (also called a lane reduction, road rechannelization or road conversion) is a technique in transportation planning whereby the number of travel lanes and/or effective width of the road is reduced in order to achieve systemic improvements. Techniques A typical road diet technique is to reduce the number of lanes on a roadway cross-section. One of the most common applications of a road diet is to improve safety or provide space for other modes of travel. For example, a two-way, four lane road might be reduced to one travel lane in each direction. The freed-up space is then used to provide or enhance some of the following features: Adding or widening of footpaths/sidewalks Adding or widening of boulevards (landscaping strips) Adding cycle lanes on one or both sides of the road Adding reserved tramtracks, usually in the middle of the road Widening remaining traffic lanes (if previously unsafely narrow to allow four lanes) Adding a center turn lane / flush traffic median for turning traffic Adding a reversible center lane Conversion of the rightmost or leftmost travel lane to a breakdown lane (The Lodge Freeway in metro Detroit is an example of this after I-96, the Jeffries Freeway, was built.) If properly designed, traffic does not divert to other streets after a road diet, because the road previously provided excessive capacity. In other scenarios, reduction of traffic (either local traffic or overall traffic) is intended in the scheme. Road diets are usually successful on roads carrying fewer than 19,000 vehicles per day. Road diets can succeed at volumes up to about 23,000 vehicles per day. However, more extensive reconstruction is needed. Examples include replacing signals with roundabouts, traffic calming on parallel streets to discourage traffic from diverting away from the main road, and other means to keep traffic moving smoothly and uniformly. Lane diets In a lane diet, the width of a lane is decreased to reduce vehicle speeds and yield space for other use. Typically vehicular travel lane widths are narrowed to no more than , and left turn (in countries where drivers use the right-hand side of the road) storage lanes to . Resulting space can be applied to pedestrian refuges, medians, sidewalks, shoulders, parking, or bike lanes. Benefits Researchers and the U.S. Department of Transportation (Federal Highway Administration) have found that road diets can be expected to reduce overall crash frequency by 19% to 43%,