Road diet

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Road diet in Davis CA.jpg
A road in Davis, California, with four lanes curb to curb
After DavisCA RoadDiet.jpg
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 of travel lanes and/or effective width of the road is reduced in order to achieve systemic improvements.

Contents

Techniques

Pocernicka Street in Prague used to be four lanes wide. In 2010s, it got two parking lanes and bicycle lanes on each side of the road Cyklopruh Strasnice 1.JPG
Počernická Street in Prague used to be four lanes wide. In 2010s, it got two parking lanes and bicycle lanes on each side of the road

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. [1] For example, a two-way, four lane road might be reduced to one travel lane in each direction. [2] The freed-up space is then used to provide or enhance some of the following features:

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.[ citation needed ]

Lane diets

In a lane diet, the width of a lane is decreased to reduce vehicle speeds and yield space for other use. [3] Typically vehicular travel lane widths are narrowed to no more than 10 feet (3.0 m), and left turn (in countries where drivers use the right-hand side of the road) storage lanes to 9 or 10 feet (2.7 or 3.0 m).[ citation needed ] Resulting space can be applied to pedestrian refuges, medians, sidewalks, shoulders, parking, or bike lanes. [3]

Impacts

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%, with the higher crash reductions occurring in small urban areas than in metropolitan areas. [4]

Dan Burden and Peter Lagerwey a 1999 article noted that in two cases, 95% of residents were initially opposed to roadway constriction. [5] 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. [6]

Implementation examples by country

United Kingdom

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. [7]

United States

Among American cities, San Francisco has completed the most road diet projects, over 40 since the late 1970s. [8] 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. [9]

San Jose, California has implemented several road diets since November 2011, when the City Council unanimously adopted its "Envision 2040" General Plan, [10] which calls for road diets on streets with excess vehicle capacity "to provide wider sidewalks, bicycle lanes, transit amenities, and/or landscaping". [11] Road diets were completed on 3rd, 4th, 10th, and 11th streets in August 2012, [12] [13] and on Hedding Street in July 2013. [14]

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. [15]

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 [16] 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. [17] Lane reductions were approved and then implemented on Charleston Road in 2006, [18] Arastradero Road in 2010, [19] and Deer Creek Road in 2011. [20]

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. [21]

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. [22]

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. [23]

See also

Related Research Articles

<span class="mw-page-title-main">Palo Alto, California</span> City in California, United States

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.

<span class="mw-page-title-main">Traffic calming</span> Road design measures that raise the safety of pedestrians and motorists

Traffic calming uses physical design and other measures to improve safety for motorists, pedestrians and cyclists. It has become a tool to combat speeding and other unsafe behaviours of drivers in the neighbourhoods. 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.

In economics, induced demand – related to latent demand and generated demand – is the phenomenon whereby an increase in supply results in a decline in price and an increase in consumption. In other words, as a good or service becomes more readily available and mass produced, its price goes down and consumers are more likely to buy it, meaning that the quantity demanded subsequently increases. This is consistent with the economic model of supply and demand.

<span class="mw-page-title-main">Curb extension</span> Traffic calming measure

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.

<span class="mw-page-title-main">Living street</span> Traffic calming in spaces shared between road users

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.

<span class="mw-page-title-main">Vehicular cycling</span> Practice of riding bicycles on roads while obeying roadway rules

Vehicular cycling is the practice of riding bicycles on roads in a manner that is in accordance with the principles for driving in traffic, and in a way that places responsibility for safety on the individual.

<span class="mw-page-title-main">Bicycle transportation planning and engineering</span>

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.

<span class="mw-page-title-main">Los Gatos Creek Trail</span> Pedestrian and bicycle trail in Santa Clara County, CA

The main segment of the Los Gatos Creek Trail is a 9.7-mile (15.6 km) pedestrian and bicycle trail that runs through western Santa Clara County in California. It runs from Lexington Reservoir in Los Gatos, California through Campbell, California to Meridian Avenue in San Jose, California alongside Los Gatos Creek.

<span class="mw-page-title-main">Washington Avenue Bridge (Minneapolis)</span> Bridge in Minneapolis, Minnesota

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<span class="mw-page-title-main">Bicycle safety</span> Safety practices to reduce risk associated with cycling

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.

<span class="mw-page-title-main">Bicycle boulevard</span> Street designed as a bicycle route

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 allow local motor-vehicle traffic. 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.

<span class="mw-page-title-main">Transportation in the San Francisco Bay Area</span> Overview of transportation in the San Francisco Bay Area, California, United States

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<span class="mw-page-title-main">Cycle track</span> Cycleway between a road and sidewalk, protected by barriers

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.

<span class="mw-page-title-main">Complete streets</span> Transportation policy and design approach

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.

<span class="mw-page-title-main">Shared lane marking</span>

A shared lane marking, shared-lane marking, or sharrow is a street marking installed at various locations worldwide, such as New Zealand, Australia, Canada, Spain, and the United States. This marking is placed in the travel lane to indicate where people should preferably cycle.

<span class="mw-page-title-main">Cycling in New York City</span>

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.

<span class="mw-page-title-main">Cycling infrastructure</span> Facilities for use by cyclists

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.

<span class="mw-page-title-main">Safety of cycling infrastructure</span> Overview of bicycle safety concerns

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.

<span class="mw-page-title-main">Cycling in San Jose, California</span>

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.

<span class="mw-page-title-main">Stroad</span> Type of thoroughfare

A stroad is a type of thoroughfare that is a mix between a street and a road. 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. Urban planners have criticized stroads for their safety issues and poor efficiency. While streets provide access to shops and residences at safe traffic speeds, and roads can efficiently move traffic at high speed and volume, stroads pose dangers to drivers and pedestrians and are also prone to congestion.

References

  1. McGreevy, Patrick (May 27, 2019). "Using California gas tax to reduce traffic lanes? Not how it should be spent, some say". Los Angeles Times . Retrieved May 28, 2019.
  2. "Road Diet Guide - Car Free America". Car Free America. Retrieved 31 October 2017.
  3. 1 2 How's That Diet Working: Performance of Virginia Road Diets (PDF) (Report). Virginia Transportation Research Council. April 2020. Retrieved 12 October 2022. 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.
  4. Turner-Fairbank Highway Research Center (June 2010). "Evaluation of Lane Reduction 'Road Diet' Measures on Crashes". Federal Highway Administration. FHWA-HRT-10-053.
  5. Burden, Dan & Lagerwey, Peter (March 1999). "Road Diets: Fixing the Big Roads" (PDF). Walkable Communities.
  6. Turner-Fairbank Highway Research Center (March 2004). "Evaluation of Lane Reduction 'Road Diet' Measures and Their Effects on Crashes and Injuries". Federal Highway Administration. FHWA-HRT-04-082.
  7. Jones, Harrison (14 May 2020). "Road turns into giant cycle lane to make social distancing easier". Metro. Retrieved 3 May 2021.
  8. Reisman, Will (24 August 2012). "Road Diets Used as Tool for Reclaiming Neighborhoods in San Francisco". San Francisco Examiner. Retrieved 10 February 2014.
  9. Roth, Matthew (31 March 2010). "San Francisco Planners Proud of Long List of Road Diets". Streetsblog San Francisco. Retrieved 10 February 2014.
  10. Seipel, Tracy (31 October 2011). "San Jose's Updated General Plan Emphasizes 'Smart Growth,' Healthier Communities". San Jose Mercury News. Retrieved 10 February 2014.
  11. Envision San Jose 2040. City of San Jose. November 2011. ch. 6, p. 38. Retrieved 10 February 2014.
  12. Diaz, Kim (13 August 2012). "New Bike Lanes Introduced to Downtown Streets". SanJose.com. Retrieved 10 February 2014.
  13. Diaz, Kimberley (29 August 2012). "New Bike Lanes in San Jose". Spartan Daily. Archived from the original on 22 February 2014. Retrieved 10 February 2014.
  14. Masoner, Richard (19 July 2013). "Hedding Street Green Bike Lane Ribbon Cutting Sunday". Cyclelicious. Retrieved 10 February 2014.
  15. "More people are dying on L.A.'s streets despite a push to eliminate traffic fatalities". Los Angeles Times. 25 April 2019.
  16. Dong, Jocelyn (8 December 2004). "Narrowing Middlefield Sparks Wide Outcry". Palo Alto Weekly. Retrieved 10 February 2014.
  17. "Pedestrian Killed while Crossing Embarcadero Is Identified". Palo Alto Online. 28 January 2013. Retrieved 10 February 2014.
  18. Trout, Becky (14 May 2008). "Charleston Road Safer, Better after Lane Changes, Council Agrees". Palo Alto Weekly. Retrieved 8 October 2011.
  19. Transportation Division (14 October 2010). "Community Meeting Notice, Arastradero Road Restriping–Trial Project" (Press release). City of Palo Alto. Retrieved 8 October 2011.
  20. Sheyner, Gennady (29 July 2011). "Palo Alto Speeds ahead with Traffic-Calming Projects". Palo Alto Weekly. Retrieved 8 October 2011.
  21. Redesigned Nebraska Avenue Significantly Safer, The Tampa Tribune. Retrieved 2015-06-15.
  22. Rutland scrapping plans for bike lanes along Woodstock Ave, WCAX. Retrieved 2015-06-15.
  23. Road Diets lead to big fat safety concerns for emergency responders. https://www.desmoinesregister.com/story/opinion/columnists/iowa-view/2019/02/13/road-diets-lead-safety-concerns-emergency-response-traffic/2862872002/