A recent post by FHWA administrator Gregory Nadeau for the Fast Lane blog describes road diets and their benefits in relation to safety and traffic operations, traffic calming, the provision of bicycle facilities, and multimodal street design.  Road diets – or road "right-sizing" – involve reconfiguring the roadway by removing one or more motor vehicle lanes (often adding bike lanes). In addition to lane reductions, reducing lane widths can result in lower travel speeds (which better align with posted speed limits and typically result in less severe injuries in the event of a crash). Road diets can also reduce pedestrian crossing distances, which can in turn result in fewer pedestrian crashes. Other benefits include:

• Space gained by removing one lane can be used to provide bike lanes or shoulders on both sides of the road
• Bike lanes increase separation from traffic for pedestrians and improve the comfort of walking on sidewalks
• Center turn lanes, commonly implemented in road diets, reduce crashes and improve roadway operation by reducing conflicts with turning vehicles
• One travel lane in each direction allows drivers following posted speed limits to set the prevailing speed
• A center turn lane can be converted to a raised median and provide pedestrian refuge islands at crossing locations, making it easier for pedestrians to cross the street and adding traffic calming measures

Road diets, when implemented as part of planned resurfacing, typically add little or no extra cost. Road diets that provide a center turn lane typically do not reduce vehicle throughput on a roadway.