Further Reading on Rightsizing
This animated video – narrated by urban planner Jeff Speck – describes four of the most common and most effective road-diet redesigns.
Side impact- and turn-related crash rates are lowest at intersections where average lane widths are between 10 and 10.5 feet, according to a study presented at the Canadian Institute of Transportation’s annual meeting in June 2015. This challenges the long-held, but often disputed, assumption that wider lanes are safer.
The Road Diet Desk Reference is a resource to assist transportation agencies during their decision-making process in regards to considering, implementing, and evaluating Road Diet conversions. The information in the document is derived from the Road Diet Informational Guide (see below).
This comprehensive guide covers the full range of road diet considerations well beyond their proven safety benefits. The guide details the history of road diets, the reasons to consider implementing a road diet, how to determine the feasibility of a project, how to design a road diet, and how to measure the effectiveness of a project. The effects on various modes including rail and freight are laid out, as well as operational and capital concerns such as LOS and ROW acquisition.
This is a pre-intervention guide to evaluating a potential “road diet”. It is important to analyze and understand the effects of the proposed change, obtain input from the community stakeholders, and ensure the appropriate elements are included in the project. Improvements to intersection turn lanes, signing, pavement markings, traffic control devices, transit stops, and pedestrian and bicyclist facilities may be needed to support this concept. The audience best served by this report are planners, roadway designers, and transportation engineers, whether at the state or local level.
This Highway Safety Information System (HSIS) summary replaces an earlier one, Evaluation of Lane Reduction “Road Diet” Measures and Their Effects on Crashes and Injuries (FHWA-HRT-04-082), describing an evaluation of “road diet” treatments in Washington and California cities. This summary reexamines those data using more advanced study techniques and adds an analysis of road diet sites in smaller urban communities in Iowa. This report is useful as a metric for planners, roadway designers, and transportation engineers when considering the size, or type of conversion necessary for a project.
This report has been developed in response to widespread interest for improving both mobility choices and community character through a commitment to creating and enhancing walkable communities. Many agencies will work towards these goals using the concepts and principles in this report to ensure the users, community and other key factors are considered in the planning and design processes used to develop walkable urban thoroughfares.
The city of Austin released a report analyzing 37 Rightsizing projects implemented between 1999 and 2014. The report highlights the positive impacts Rightsizing has had on on traffic operations, safety, and bicycle use.
The NACTO Urban Street Design Guide shows how Rightsizing techniques can be used to improve Downtown Thoroughfares