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 to achieve proven improvements, including a statistically attested crash reduction rate of 19% to 47%. [1]
Reducing the number of lanes on a roadway cross-section is a typical road diet technique. One of the most common applications of a road diet is to improve safety or provide space for other modes of travel. [2] For example, a two-way, four lane road might be reduced to one travel lane in each direction. [3] 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, but 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.[ citation needed ]
In a lane diet, the width of a car lane is decreased to reduce vehicle speeds and accidents [1] and provide space for other use. [4] Typically vehicular travel lane widths are narrowed to no more than 9.1 feet (2.8 m), [5] and left turn (in countries where cars travel on the right-hand side of the road) storage lanes between 9 and 10 feet (2.7 and 3.0 m). [6] The resulting extra non-car space can be used for pedestrian zones or refuges, medians, sidewalks, shoulders, parking, or bike lanes. [4]
After reducing the number and/or the width of lanes, the freed-up space is used to provide or enhance some of the following features:
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 47%, [1] with the higher crash reductions occurring in small urban areas than in metropolitan areas. [7]
Dan Burden and Peter Lagerwey (in a 1999 article) noted that, after a road diet, nearly 95% of those fearing the change were openly thankful, [8] and that these changed roads " set the stage for millions or megamillions of dollars in new commercial and residential development ". [9]
Additional studies have shown that road diets often achieve these positive effects without reducing traffic volumes.
A 2004 study by the Federal Highway Administration found that road diets decreased the risk of collisions and serious injury. When average daily traffic exceeds 20,000 vehicles a day, however, this increase in safety comes with the tradeoff of increased congestion and the possibility of diverting traffic to alternate routes. [10]
In the centre of Sinchon-dong, Seoul, (South Korea), a road diet has been achieved in 2014. After 6 months, traffic congestion eased substantially, leading to a reduction of accidents by 34% from the previous year. In a survey, visitor satisfaction in 2014 was at 70% (compared to 14% in 2013). Business boomed for shops with shoppers rising by 28.9% in 2014 (compared to 2013). [11]
During the COVID-19 pandemic London implemented a number of road diets to give more space to active travel modes such as bicycle lanes, on a number of its roads. For example, the formerly three-lane northbound carriageway of Park Lane was reduced to one lane for motor traffic, one bus lane and one segregated cycle way. [12]
Among American cities San Francisco has completed the most road diet projects, over 40 since the late 1970s. [13] Valencia Street, which was reduced from four to two travel lanes with a center turn lane and bike lanes added in March 1999, has become a national model for traffic engineers of the common "4-to-3 lane" road diet type. [14]
San Jose, California has implemented several road diets since November 2011, when the City Council unanimously adopted its "Envision 2040" General Plan, [15] which calls for road diets on streets with excess vehicle capacity "to provide wider sidewalks, bicycle lanes, transit amenities, and/or landscaping". [16] Road diets were completed on 3rd, 4th, 10th, and 11th streets in August 2012, [17] [18] and on Hedding Street in July 2013. [19]
Constricting traffic arteries has been controversial in Los Angeles, California, where traffic fatalities increased 32% since beginning its Vision Zero road diet plan in 2015. [20]
Palo Alto, California has studied reducing the number of travel lanes to improve safety on some of its busiest streets since adopting a new Comprehensive Plan in 1998. Design plans were made for road diets on Embarcadero Road and Middlefield Road [21] in the early 2000s, but were never brought to the city council for approval. 75-yr-old local resident Ming Yuan Zuo was killed by a pickup truck driver while walking across Embarcadero Road in January 2013. [22] Lane reductions were approved and then implemented on Charleston Road in 2006, [23] Arastradero Road in 2010, [24] and Deer Creek Road in 2011. [25]
In Tampa, Florida, Nebraska Avenue between its intersection with Hillsborough Avenue (US 92-US 41-FL 600) and Adamo Drive was reduced from four to three lanes, complete with bicycle lanes, a left turn lane and embedded bus stops for HART buses. Construction was completed in 2009. [26]
In Rutland, Vermont, the city briefly converted Woodstock Avenue from a four-lane road to a three-lane road with bicycle lanes on each side. However, due mainly to opposition from businesses alongside the road in June 2014, Woodstock Avenue was returned to its previous four-lane configuration. [27]
In Waverly, Iowa the city converted Bremer Avenue from a four-lane road to a three-lane road with a safety buffer on each side. The city faced criticism due to some citizens’ belief the change has caused slower emergency response time. [28]
Traffic comprises pedestrians, vehicles, ridden or herded animals, trains, and other conveyances that use public ways (roads/sidewalks) for travel and transportation.
A sidewalk, pavement, footpath in Australia, India, New Zealand and Ireland, or footway is a path along the side of a road. Usually constructed of concrete, pavers, brick, stone, or asphalt, it is designed for pedestrians. A sidewalk is normally higher than the roadway, and separated from it by a kerb. There may also be a planted strip between the sidewalk and the roadway and between the roadway and the adjacent land.
Palo Alto is a charter city in the northwestern corner of Santa Clara County, California, United States, in the San Francisco Bay Area, named after a coastal redwood tree known as El Palo Alto.
Traffic calming uses physical design and other measures to improve safety for motorists, car drivers, pedestrians and cyclists. It has become a tool to combat speeding and other unsafe behaviours of drivers. It aims to encourage safer, more responsible driving and potentially reduce traffic flow. Urban planners and traffic engineers have many strategies for traffic calming, including narrowed roads and speed humps. Such measures are common in Australia and Europe, but less so in North America. Traffic calming is a calque of the German word Verkehrsberuhigung – the term's first published use in English was in 1985 by Carmen Hass-Klau.
A curb extension is a traffic calming measure which widens the sidewalk for a short distance. This reduces the crossing distance and allows pedestrians and drivers to see each other when parked vehicles would otherwise block visibility. The practice of banning car parking near intersections is referred to as daylighting the intersection.
A living street is a street designed with the interests of pedestrians and cyclists in mind by providing enriching and experiential spaces. Living streets also act as social spaces, allowing children to play and encouraging social interactions on a human scale, safely and legally. Living streets consider all pedestrians granting equal access to elders and those who are disabled. These roads are still available for use by motor vehicles; however, their design aims to reduce both the speed and dominance of motorized transport. The reduction of motor vehicle dominance creates more opportunities for public transportation.
Bike lanes (US) or cycle lanes (UK) are types of bikeways (cycleways) with lanes on the roadway for cyclists only. In the United Kingdom, an on-road cycle-lane can be firmly restricted to cycles or advisory. In the United States, a designated bicycle lane or class II bikeway (Caltrans) is always marked by a solid white stripe on the pavement and is for 'preferential use' by bicyclists. There is also a class III bicycle route, which has roadside signs suggesting a route for cyclists, and urging sharing the road. A class IV separated bike way (Caltrans) is a bike lane that is physically separate from motor traffic and restricted to bicyclists only.
Bicycle transportation planning and engineering are the disciplines related to transportation engineering and transportation planning concerning bicycles as a mode of transport and the concomitant study, design and implementation of cycling infrastructure. It includes the study and design of dedicated transport facilities for cyclists as well as mixed-mode environments and how both of these examples can be made to work safely. In jurisdictions such as the United States it is often practiced in conjunction with planning for pedestrians as a part of active transportation planning.
Bicycle safety is the use of road traffic safety practices to reduce risk associated with cycling. Risk can be defined as the number of incidents occurring for a given amount of cycling. Some of this subject matter is hotly debated: for example, which types of cycling environment or cycling infrastructure is safest for cyclists. The merits of obeying the traffic laws and using bicycle lighting at night are less controversial. Wearing a bicycle helmet may reduce the chance of head injury in the event of a crash.
A bicycle boulevard, sometimes referred to as a neighborhood greenway, neighborway, neighborhood bikeway or neighborhood byway is a type of bikeway composed of a low-speed street which has been "optimized" for bicycle traffic. Bicycle boulevards discourage cut-through motor-vehicle traffic but may allow local motor-vehicle traffic at low speeds. They are designed to give priority to bicyclists as through-going traffic. They are intended as a low-cost, politically popular way to create a connected network of streets with good bicyclist comfort and/or safety.
People in the San Francisco Bay Area rely on a complex multimodal transportation infrastructure consisting of roads, bridges, highways, rail, tunnels, airports, seaports, and bike and pedestrian paths. The development, maintenance, and operation of these different modes of transportation are overseen by various agencies, including the California Department of Transportation (Caltrans), the Association of Bay Area Governments, San Francisco Municipal Transportation Agency, and the Metropolitan Transportation Commission. These and other organizations collectively manage several interstate highways and state routes, eight passenger rail networks, eight trans-bay bridges, transbay ferry service, local and transbay bus service, three international airports, and an extensive network of roads, tunnels, and bike paths.
A cycle track or cycleway (British) or bikeway, sometimes historically referred to as a sidepath, is a separate route for cycles and not motor vehicles. In some cases cycle tracks are also used by other users such as pedestrians and horse riders. A cycle track can be next to a normal road, and can either be a shared route with pedestrians or be made distinct from both the pavement and general roadway by vertical barriers or elevation differences.
Complete streets is a transportation policy and design approach that requires streets to be planned, designed, operated and maintained to enable safe, convenient and comfortable travel and access for users of all ages and abilities regardless of their mode of transportation. Complete Streets allow for safe travel by those walking, cycling, driving automobiles, riding public transportation, or delivering goods.
Cycling in New York City is associated with mixed cycling conditions that include dense urban proximities, relatively flat terrain, congested roadways with stop-and-go traffic, and streets with heavy pedestrian activity. The city's large cycling population includes utility cyclists, such as delivery and messenger services; cycling clubs for recreational cyclists; and increasingly commuters. Cycling is increasingly popular in New York City; in 2018 there were approximately 510,000 daily bike trips, compared with 170,000 daily bike trips in 2005.
Toronto, Ontario, like many North American cities, has slowly been expanding its purpose-built cycling infrastructure. The number of cyclists in Toronto has been increasing progressively, particularly in the city's downtown core. As cycling conditions improve, a cycling culture has grown and alternatives such as automobiles are seen as less attractive. The politics of providing resources for cyclists, particularly dedicated bike lanes, has been contentious, particularly since the 2010s.
Cycling infrastructure is all infrastructure cyclists are allowed to use. Bikeways include bike paths, bike lanes, cycle tracks, rail trails and, where permitted, sidewalks. Roads used by motorists are also cycling infrastructure, except where cyclists are barred such as many freeways/motorways. It includes amenities such as bike racks for parking, shelters, service centers and specialized traffic signs and signals. The more cycling infrastructure, the more people get about by bicycle.
A protected intersection or protected junction, also known as a Dutch-style junction, is a type of at-grade road junction in which cyclists and pedestrians are separated from cars. The primary aim of junction protection is to help pedestrians and cyclists be and feel safer at road junctions.
There is debate over the safety implications of cycling infrastructure. Recent studies generally affirm that segregated cycle tracks have a better safety record between intersections than cycling on major roads in traffic. Furthermore, cycling infrastructure tends to lead to more people cycling. A higher modal share of people cycling is correlated with lower incidences of cyclist fatalities, leading to a "safety in numbers" effect though some contributors caution against this hypothesis. On the contrary, older studies tended to come to negative conclusions about mid-block cycle track safety.
The American city of San Jose, California has various cycling routes on roads and trails used by both commuters and recreational riders. The city has plans to expand the current 285 miles (459 km) of bike lanes to 400 miles (640 km), and the current 60 miles (97 km) of trails to 100 miles (160 km). San Jose was ranked as a bronze-level bicycle-friendly community by the League of American Bicyclists.
A stroad is a type of street–road hybrid. Common in the United States and Canada, stroads are wide arterials that often provide access to strip malls, drive-throughs, and other automobile-oriented businesses. Stroads have been criticized by urban planners for their safety issues and inefficiencies. While streets serve as a destination and provide access to shops and residences at safe traffic speeds, and roads serve as a high-speed connection that can efficiently move traffic at high speed and volume, stroads are often expensive, inefficient, and dangerous.
A lane diet is a related term referring to the narrowing rather than removal of travel lanes to accommodate bicycle lanes, turn lanes, parking lanes, or traffic calming elements.