Speed Reductions

Strategies that Reduce Traffic Speeds

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TDM Encyclopedia

Victoria Transport Policy Institute

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Updated 6 September 2019


This chapter discusses various strategies for reducing traffic speeds, their effects on total vehicle travel and other impacts. Reducing traffic speeds tends to improve walking and cycling conditions, increase safety, reduce air and noise pollution, encourage more compact development, and reduce total automobile travel.

 

Description

Various strategies can help reduce traffic speeds:

 

·         Traffic Calming and Complete Streets policies implement roadway designs that reduce traffic speeds.

 

·         Speed limits can be reduced.

 

·         Speed enforcement can be improved, using conventional or newer techniques described below.

 

·         New and existing streets can be designed to be narrower.

 

·         Signage can be improved, including signs that display the speed of vehicles as they drive by.

 

·         Various strategies can be used to reduce traffic speeds on arterials, highways and rural roadways (DEA 1999; Kamyb, et al. 2003; ITF 2018).

 

·         Various rural roadway design changes (Austroads 2014)

 

·         Driver education and public service announcements can be used to discourage speeding.

 

·         Traffic signals synchronization can be optimized for lower traffic speeds. Signal progression on urban arterials can be set so that vehicles that maintain legal speeds avoid stopping.

 

·         Vehicles can incorporate a system that automatically alerts drivers when they exceed speed limits, or prevents speeding altogether.

 

·         Higher fuel prices tend to reduce traffic speeds. A $0.50 per gallon fuel price increase is found to reduce median uncongested highway traffic speeds by about three-quarters of a mile-per-hour (CBO 2008).

 

 

Drivers tend to maintain a speed that feels comfortable, based on the design (lane width, visibility, clearance) and use (traffic volumes, turning activity, pedestrian activity) of each stretch of roadway. As a result, simply reducing posted speed limits may do little to reduce actual traffic speeds. Effective speed reduction generally requires changing roadway design, or significantly increasing enforcement.

 

Below are common traffic law enforcement techniques (Coulter Transportation Consulting 2004):

 

·         Radar. Police radar transmits a microwave signal at a known frequency and then receives the signal reflected back from the object. The signal frequency returns to the radar unit in proportion to the speed of the moving vehicle, and the vehicle's speed is displayed. Radar signals also can be used to trigger roadside warning signs that display vehicle speeds to drivers.

 

·         Laser. A narrow band of light is transmitted to a targeted vehicle and returned by it, and the speed of the vehicle is displayed for the officer. These devices are similar in size and weight to police radar. LIDAR (Light Distance and Ranging) devices send out and retrieve a rapid series of light pulses to and from a target vehicle, using a time/distance calculation to measure speed based on the change in consecutive measurements. Laser devices have been used in the United States for speed enforcement since 1990.

 

·         Speed Cameras. Radar signals can be used to trigger cameras that photograph speeding vehicles as they pass a specified point. These devices use a low-powered doppler radar speed sensor to detect speeding vehicles and trigger a motor-driven camera and flash unit to photograph vehicles traveling faster than a set speed. The date, time, and speed are recorded along with a photo.

 

·         VASCAR. A vehicle average speed calculator and recorder uses a portable computer to accurately clock, calculate, and display speed based on the time a vehicle takes to travel a known length of road.

 

·         Aerial speed Measurement. Officers in light aircraft measure vehicle speed based on the time it takes to travel between two or more pavement markings spaced a known distance apart.

 

·         Variable Speed Limits (VSL). This is a type of Intelligent Transportation System (ITS) that utilizes traffic speed and volume detection, weather information, and road surface condition technology to determine appropriate speeds at which drivers should be traveling, given current roadway and traffic conditions.

 

·         Other Speed Measures. These include electronic roadside signs displaying vehicle speeds or other messages and other types of roadway design measures.

 

 

Various studies indicate that roadway design factors affect traffic speeds (GRSP 2008). Ivan, Garrick and Hanson (2009) observed traffic at about 300 locations in urban, suburban and rural areas across Connecticut, at locations without horizontal curves or traffic control devices. They found strong statistical relationships between traffic speeds and various roadway design factors. Higher average traffic speeds are associated with wide shoulders, large building setbacks and a residential location. Lower average traffic speeds are associated with on-street parking, sidewalks and a downtown or commercial location. These findings suggest that drivers slow down where the road feels “hemmed-in” or there is noticeable street activity, and they speed up where the road feels “wide open” or street activity is less noticeable.

 

Table 1            Responses To Opponents (SAHF 2011)

Opponents Say

Response

Lowering speed limits will cause congestion and increase travel time

 

In busy urban environments the average journey speeds are considerably less than the set speed limits.

Data shows that lowering speed limits in built up urban areas has a minimal impact on drivers’ travel time.

Lower speed limits reduce delays – meaning smoother progression of traffic flow or harmonic traffic rhythm – under medium congestion levels.

Adjusting traffic lights in slower speed areas will minimise delays, generate smoother traffic flow and relieve congestion.

Drivers assume that driving faster will reduce overall travel time – not true in urban environments! Travel time is mostly influenced by frequent stopping or slowing down, such as at intersections and rail crossings.

Traffic congestion in urban areas is a major consideration for assessing various modes of transport. Lowering speed limits will encourage more walking and cycling, and this shift will add capacity to our roads and reduce the strain on public transport services.

Changing speed limits will cause driver confusion

Speed limits should be one part of an overall strategy to calm traffic and improve the walking and cycling environments.

Cars are more fuel efficient at higher speeds – fuel consumption and emissions will be higher

Reducing speeds is not just about reducing pollution it’s about driver safety, pedestrian and cyclist safety, improving health and increasing trader business.

Emissions may be reduced under a 40 km/h speed limit compared to a 60 km/h.

If people shift from cars to active transport there will be reduced noise and air pollution.

Lower speed coupled with signal coordination can actually reduce emissions and fuel consumption.

Aggressive driving such as accelerating hard from traffic lights and lane changing is a much bigger factor in fuel consumption than vehicle speed.

Reducing speed limits are just about raising revenue through speeding fines

No, it’s about putting people and their safety first.

It will improve the walkability and liveability of the city.

 

 

 

How It Is Implemented

Speed reduction programs are usually implemented by local or state/provincial transportation or law enforcement agencies (GRSP 2008; SAHF 2012). Legislative action and additional funding may be required to implement some policy changes or new technologies.

 

 

Travel Impacts

Studies indicate the elasticity of vehicle travel with respect to travel time is  –0.2 to –0.5 in the short run and –0.7 to –1.0 over the long run, meaning that a 10% reduction in average traffic speeds reduces affected vehicle travel by 2-5% during the first few years, and up to 7-10% over a longer time period (Transport Elasticities). This occurs because motorists generally measure travel in terms of time as well as mileage (for example, a particular destination may be described as “20-minutes from town”) so as traffic speeds increase motorists tend to travel more miles.

 

A comprehensive speed reduction program that significantly reduces traffic speeds on all roads can reduce automobile travel, encourage use of alternative modes (particularly walking and cycling), and help create more Accessible land use patterns, but in practice most speed reduction programs have relatively modest impacts because they apply only to a specific area and so only affect the portion of total vehicle travel. A Traffic Calming program or reduction in posted speeds on a few roads may shift travel to other areas rather than reduce total vehicle travel.

 

Table 2          Travel Impact Summary

Objective

Rating

Comments

Reduces total traffic.

1

 

Reduces peak period traffic.

1

 

Shifts peak to off-peak periods.

0

 

Shifts automobile travel to alternative modes.

1

 

Improves access, reduces the need for travel.

1

 

Increased ridesharing.

1

 

Increased public transit.

1

 

Increased cycling.

2

 

Increased walking.

2

 

Increased Telework.

1

 

Reduced freight traffic.

1

 

Rating from 3 (very beneficial) to –3 (very harmful). A 0 indicates no impact or mixed impacts.

 

 

Benefits and Costs

Benefits include increased Safety, reduced total vehicle travel, improved Walking and Cycling conditions, and environmental benefits. Speed Reductions can improve urban Livability, which encourages more efficient Land Use patterns (DfT 2004). Cortright (2017) found that residents of urban regions with higher average traffic speeds (indicating that they have more roadway capacity, less congestion and more sprawled development patters) tend to drive more annual vehicle-miles and are less satisfied with their transportation systems than residents of areas with slower speeds, indicating that the motorists are burdened by total travel time costs rather than just congestion delays, as is assumed by indicators such as roadway level-of-service.

 

Traffic speed is a major contributor to traffic accident risk, particularly for pedestrians and cyclists (WHO 2004). The Power Model states that a given relative change in the mean speed of traffic is associated with a relative change in the number of accidents or accident victims by means of a power (exponential) function (Elvik 2005). This indicates that a 10% change in the mean speed of traffic is likely to have a greater impact on traffic fatalities than a 10% change in traffic volume. Speed is likely to be the single most important determinant of the number of traffic fatalities. Speeding is a significant road safety problem in many countries, and reducing average traffic speeds by just 5% can reduce fatalities by approximately 20% (McMillan and Cooper 2019; OECD/ECMT 2006).

 

Even modest speed reductions can prevent many collisions, and reduce the severity of damages and injuries that result when crashes occur, and are particularly effective at reducing injuries to pedestrians and cyclists (Stuster and Zail Coffman 1998; Elvik 2001; Gårder 2004; IIHS 2000; ITF 2018; Racioppi, et al. 2004). Based on analysis of several data sets that relate collision speeds and pedestrian injury severity, About 5% of pedestrians would die when struck by a vehicle traveling 20 mph, 40% for vehicles traveling 30 mph, 80% for vehicles traveling 40 mph, and nearly 100% for speeds over 50 mph.

 

Analysis by Redelmeier and Bayoumi (2010) using U.S. data suggested that 1 hour spent driving was associated with approximately 20 minutes reduction in life expectancy due to crash risk. For the average driver, each one kilometer per hour (0.6-mph) increase in driving speed yielded a 26-second increase in total expected lost time because the savings from reduced travel time were more than offset by time lost to increased crashes. A 3 kilometer-per-hour (1.8-mph) decrease in average driving speed yielded the least amount of total time lost. This speed yielded about 11,000 fewer daily crashes. This analysis indicates that U.S. drivers travel slightly too fast and could improve overall life expectancy by decreasing their average speed slightly.

 

Annual crash rates per lane-mile tend to increase with lane width, and are highest on wider, lower volume, straight streets that have the highest speeds (Swift, Painter and Goldstein 2006; Zegeer, et al. 1994; AARP 2009). 24-foot streets appear to have the lowest accident rates. This suggests that narrower street designs and traffic calming can increase road safety.

 

Narrower roads with fewer traffic lanes are associated with significantly lower crash risk to pedestrians than wider roads (Zegeer, et al. 2002; AARP 2009). Converting four-lane urban arterials to two lanes plus a center turn lane tends to reduce collisions about 1/3, improves pedestrian travel and causes only minor reductions in traffic volumes (Welsh 2001). Wei and Lovegrove (2010) found that 3-way offset, and fused grid patterns significantly improve road safety, by as much as 60% compared to grid and culs-de-sac street designs. These results do not account for the additional safety benefits that result if roadway network designs that favor walking and cycling cause travel to shift from auto to non-auto modes so these can be considered lower-bound estimates of safety benefits. Taylor, et al (2000) estimate that each 1 mph reduction in average traffic provides the following reductions in vehicle accidents:

 

 

Since roadway traffic capacity is maximized at 30-45 mph, speed reductions can increase traffic flow and reduce traffic Congestion delays. Reducing traffic speeds to the 20-40 mph range tends to reduce vehicle operating costs such as vehicle wear, Energy Consumption and Pollution Emissions. Speed reductions reduce traffic noise, particularly if traffic flow is smoothed to reduce hard accelerations. Traffic speeds below about 20 mph may increase per-mile fuel consumption and emissions. Speed reductions that result in smoother traffic flow also reduce vehicle costs and emissions, while those that involve increased stopping may increase these impacts.

 

Costs include program implementation and operations, and reduced mobility for motorists. Speed law enforcement programs may be self-funding through fines.

 

Table 3          Benefit Summary

Objective

Rating

Comments

Congestion Reduction

2

Benefits are greatest for reductions from high to medium speeds.

Road & Parking Savings

0

 

Consumer Savings

1

Benefits are greatest for reductions from high to medium speeds.

Transport Choice

1

Can improve nonmotorized travel conditions.

Road Safety

3

 

Environmental Protection

2

Benefits are greatest for reductions from high to medium speeds.

Efficient Land Use

1

 

Community Livability

3

 

Rating from 3 (very beneficial) to –3 (very harmful). A 0 indicates no impact or mixed impacts.

 

 

Equity Impacts

Speed reductions tend to have mixed equity impacts. Motorists often argue that they were unfairly selected for a citation, or that speeds are unreasonably low on a particular road. They tend to reduce external costs of driving (crash risk, air, noise pollution and congestion delays), and benefit people who are transportation disadvantaged by improving walking and cycling conditions. These impacts vary depending on specific conditions.

 

Table 4          Equity Summary

Criteria

Rating

Comments

Treats everybody equally.

0

 

Individuals bear the costs they impose.

2

 

Progressive with respect to income.

0

 

Benefits transportation disadvantaged.

2

 

Improves basic mobility.

1

 

Rating from 3 (very beneficial) to –3 (very harmful). A 0 indicates no impact or mixed impacts.

 

 

Applications

Speed reductions can be implemented in virtually any geographic conditions. Federal and state policies can affect speeds on major highways. Regional and local governments tend to apply speed reduction programs on surface streets.

 

Table 5          Application Summary

Geographic

Rating

Organization

Rating

Large urban region.

2

Federal government.

1

High-density, urban.

2

State/provincial government.

2

Medium-density, urban/suburban.

2

Regional government.

3

Town.

2

Municipal/local government.

3

Low-density, rural.

2

Business Associations/TMA.

1

Commercial center.

2

Individual business.

1

Residential neighborhood.

2

Developer.

1

Resort/recreation area.

2

Neighborhood association.

2

College/university communities.

2

Campus.

2

Ratings range from 0 (not appropriate) to 3 (very appropriate).

 

 

Category

Incentive to Reduce Vehicle Use

 

 

Relationships With Other TDM Strategies

Speed Reductions support and is supported by Traffic Calming, Vehicle Restrictions, Smart Growth, New Urbanism, School Transport Management, Safety Evaluation and Campus Transportation Management.

 

 

Stakeholders

Major stakeholders include transportation planners and engineers, law enforcement officials, motorists and citizens.

 

 

Barriers To Implementation

Barriers include resistance by motorists, and technical difficulties implementing changes in road design or increased enforcement.

 

 

Best Practices

Traffic speed reductions should be implemented in a comprehensive program that includes Traffic Calming and roadway design, reduced speed limits, driver education and improved enforcement. For information on speed reduction programs see NHTSA and IIHS websites.

 

Wit and Humor

A police office pulls over a car going much slower than other traffic.

The police asks, “This is a 65 mph highway – why are you going so slow?”

The driver replies, “Officer, I saw a lot of signs that said 22, not 65.”

 “Oh, that’s not the speed limit, that’s the number of the highway you’re on!” explains the officer.

The driver replies, “Oh! Silly me! Thanks for letting me know. I’ll be more careful.”

At this point the cop looks in the backseat where two passengers are shaking and trembling.

The officer asks, “Excuse me, what’s wrong with your friends back there? They’re shaking something terrible.”

 “Oh, we just got off of highway 119,” explains the driver.

 

 

Examples and Case Studies

 

Pedestrian Safety Operations Proving Effective Pedestrian Safety Operations Proving Effective (http://www.odot.state.or.us/comm/news/2002071801.htm)

Oregon cities have been able to reduce pedestrian crashes by increasing pedestrian law enforcement. Under the Pedestrian Safety Operations (PSE) program, a decoy police officer attempts to cross in a crosswalk, with a video camera recording the event. If passing motorists fail to stop and yield as required by law, they are issued either a warning or a citation. Three years since the program was established crosswalk pedestrian injuries declined by 16% (from 348 to 293) and fatalities declined 19% (from 16 to 13).

 

Some people have criticized these as “sting” operations, but the program is not designed to surprise or entrap motorists. The purpose is to raise awareness, not write citations. Advance warning is provided through media coverage and on-site signs. Police support the program as an effective crash prevention strategy, with 31 police departments and sheriff’s offices participating in 2002.

 

We are grateful to all participating law enforcement agencies. They’ve done a great job,” said Rick Waring, Pedestrian Safety Program coordinator for ODOT. “Pedestrian safety is a serious issue in every community—people have trouble getting across their streets and they are delighted someone is doing something about it. Community response from citizens and public officials has been overwhelmingly positive,” said Waring.

 

ODOT’s pedestrian safety program also has provided specialized training for 71 police agencies and 108 officers and deputies. The goal is to teach officers to set up the operation so it is fair to motorists, yet has the desired effect of raising awareness and improving safety for pedestrians. For more information, contact the Oregon Department of Transportation Bicycle and Pedestrian Safety Program, (www.odot.state.or.us).

 

 

Speeding Contributes to One-Quarter of Fatalities, But Remains Culturally Acceptable

By Michael Brenneis

 

As a vehicle’s speed increases, it’s kinetic energy increases exponentially. Should a vehicle crash, its kinetic energy is transferred, often catastrophically, into the structure of the vehicle, its occupants, other vehicles, the surrounding built environment, or nearby pedestrians or cyclists. A small amount of speed reduction can translate into a big reduction of kinetic energy, and reduces the potential severity of a crash. Higher speed and speeding also increases stopping distance, and compresses the amount of time drivers have to react.

 

new report from the Governors Highway Safety Association (GHSA) takes a comprehensive look at speeding on American roadways, including observations about who is speeding, why they are speeding, and what can be done to reduce it.

 

A lot of people recognize that speeding is a problem, but they do it anyway. It’s not always that they’re conscious scofflaws; they may be lulled into a speeding complacency. Driving roads that are designed to encourage unsafe speeds, they grow accustomed to driving fast. And observing other drivers speeding with little consequence leads to an assumption that the risk is minimal. Some states are increasing speed limits even though higher limits have been shown to reduce safety and increase speeding. The numbers may also be under-reported. Crash reports will sometimes report speeding as “driving too fast for conditions.” GHSA recommends standardizing crash data collection.

 

Speeding mitigation has historically fallen into either an enforcement or public outreach category. Automated enforcement, increasingly shown to be an effective deterrent, faces political and popular opposition. Other technological solutions such as speed governors, or in-vehicle speed alert systems linked to GPS and high-quality speed limit maps, could be implemented or developed in connected vehicles. The GHSA also supports shifting the culture away from accepting speeding to viewing drivers who speed as wrong-doers and developing a voice for the victims of crashes due to speeding, in the same way that drunk-driver victims were previously elevated.

 

 

Speed Management for Safety (www.ite.org/technical-resources/topics/speed-management-for-safety)

The Speed Management for Safety resource hub, developed by Institute of Transportation Engineers and the Road to Zero Coalition, provides transportation professionals with tools for evaluating, designing, implementing, and enforcing safe speeds. It explores various elements of speed management:

Speed as a Safety Problem covers the relationship of speed to crash causation and fatalities.

Setting Speed Limits provides approaches and factors to determine speed limits based on various road conditions.

Measures for Managing Speed summarizes how the 3 Es — engineering, enforcement, and education — can be used to provide effective speed management and safe streets.

Creating a Speed Management Program guides creation of a comprehensive speed management program in all types of communities.

 

For additional information on speed management as it relates to Vision Zero, check out the ITE Transportation Safety webpage, the Vision Zero Network Safety over Speed webpage, and the Federal Highway Administration Speed Management Safety program. Transportation professionals can also use resources available on speed management and safety from the World Health Organization’s UN Road Safety Collaboration, the National Association of City Transportation Officials, the Governors Highway Safety Association, and the National Transportation Safety Board.

 

 

Narrower Streets Reduce Traffic Speeds and Increase Neighborhood Livability (www.ci.vancouver.wa.us/transportation/ntmp/seindex.html)

The Southeast Vancouver Neighborhood Traffic Management program in the city of Vancouver, Washington was initiated in 2002. Similar to many traffic calming exercises, it was intended to build a framework for enhanced livability in an area of Vancouver, Washington that had a tremendous range of street facilities. (The City of Vancouver is located 10 miles north of Portland, Oregon in Washington State.) In the southeast quadrant of Vancouver there are neighborhoods that are tailor-made for walking – combinations of narrow streets, traffic calming measures, trails and sidewalks with landscape strips – a design topology that encourages use of the street by residents. These enclaves of community-sensitive design are commonly surrounded by areas developed primarily in the 1970’s to 1980’s. In many of these older neighborhoods the street design appeared to be guided by a bigger is better perspective, where pedestrian facilities were not even contemplated. This range of street facilities provided a fertile test bed for research into how people perceived their streets and use them.

 

Analysis and surveys conducted for this program provide insights as to the dichotomy of perspectives individuals have for their street – as a traveler (a driver’s perception of a wide street as convenient or safe) and as a resident (a pedestrian’s perception of higher vehicle speeds as unsafe and undesirable). Based upon analysis of responses to interview surveys, many residents that thought their street was safe for one purpose (driving), also did not conduct activities on their street which would validate its safety (cross the street, have kids play in the front yard, walk). The survey produced consistent relationships – as speed, volume and street width increased, factors that influence livability (such as walking) decreased.

 

In evaluating the relationship between street width and motor vehicle speed it was found that given a consistent set of street topology characteristics, as street width increases, vehicle speed increases. The relationship was linear and basically suggests that for every 1m [3 to 4 feet] of roadway width, vehicle speeds incrementally increase 1.6 kilometers per hour [1 mile per hour]. However, more significantly the number of vehicles traveling 8 and 16 kph [5 and 10 mph] or more over the posted speed increase geometrically with street width. These higher speed vehicles are commonly the vehicles that place pedestrians at significant risk of injury or death and are the general stimulus that generates calls to city staff with complaints about drivers speeding (an indicator of lower livability). Based upon these findings, the range of 24 to 32 feet width streets appear to produce the most desirable balance of safety, pedestrian access, and vehicle maneuverability. These width findings are consistent with historical standards (1920’s) and Appleyard’s work. Had developers and jurisdictions used these guidelines, many of today’s street livability problems could have been avoided.

 

While there are numerous traffic calming measures to manage driver behavior and vehicle speed in neighborhoods, there are fewer tools available to address vehicle volume. The same surveys of residents indicated that the greatest level of street activity (including walking) occurred with street volumes less than 1,000 vehicles per day. While vehicle activity can create a sense of security, too much of a good thing seems to have the opposite effect –reduced pedestrian and resident street activity. A second analysis approach was utilized in Vancouver to test the relationship between neighborhood traffic volumes and connectivity, on the assumption that connectivity could provide the basis for reduced street volumes by better distribution or dispersion of traffic. A detailed EMME/2 travel demand forecast model was used to test connectivity options and their influence on neighborhood livability. It was found that a dense grid-like street network was not necessarily needed to provide the benefit of connectivity – but linkages about every 152 to 305 meters [500 to 1000 feet]. However, connectivity by itself was not a panacea. By combining both traffic calming and connectivity, desirable levels of motor vehicle traffic could be achieved and with less extensive neighborhood traffic management than traffic calming alone.

 

Simply narrowing streets and installing vertical or horizontal deflection traffic calming devices will not assure a livable pedestrian environment. The design of streets should consider street anatomy from a pedestrian perspective: the walls, the border area, and the crossing area. Key tools to establishing a livable walking environment in the pedestrian areas include providing adequate buffer areas, walking zones, driveway and curb ramps, and crossing treatments. These tools can be applied within standard residential street right-of-way widths (ranging from 48 feet to 56 feet) if street curb-to-curb widths are limited to the recommended 24 to 32 feet. Without these key characteristics, pedestrians can be obstructed and forced to travel in the roadway area.

 

Health Benefits of Speed Reductions (Tranter 2010)

Tranter (2010) argues that the emphasis in urban areas on increasing vehicle traffic speed and volume contributes to ill-health through its impacts on local air pollution, greenhouse gas production, inactivity, obesity and social isolation. In addition to these impacts, a heavy reliance on cars as a supposedly ‘fast’ mode of transport consumes more time and money than a reliance on supposedly slower modes of transport (walking, cycling and public transport). Using the concept of ‘effective speed’, this paper demonstrates that any attempt to ‘save time’ through increasing the speed of motorists is ultimately futile. If planners wish to provide urban residents with more time for healthy behaviours (such as exercise and preparing healthy food), then, support for the ‘slower’ active modes of transport should be encouraged.

 

 

Health Benefits of Traffic Calming (http://injuryprevention.bmj.com/content/15/6/369.full.html)

Jacobsen, Racioppi and Rutter (2009) examine the impact of vehicle traffic on levels of walking and bicycling based on a comprehensive review of medical, public health, city planning, public administration and traffic engineering technical literature.  The analysis indicates that real and perceived danger and discomfort imposed by traffic discourages walking and bicycling. Although it can be difficult to measure these effects, observed behaviour provides good evidence for these effects, with the strongest association being an inverse correlation between volumes and speeds of traffic and levels of walking and cycling. They conclude that interventions to reduce traffic speed and volume are likely to improve public health by increasing walking and bicycling activity.

 

Traffic Taming in Brasília (www.movingtheeconomy.ca/cs_brasilia.html)

Traffic Taming in Brasília was the first Brazilian experience in the control of traffic violence. In the city of Brasília, the average vehicle speed was 90 kilometres per hour and there were 3 to 4 traffic deaths each day, almost half of them pedestrians. In response to public demand, the Government of the Federal District implemented a traffic safety program in 1995 that included the installation of 330 electronic speed-controlling devices, engineering work in critical locations, and the creation of a Traffic Division with 500 police officers.

 

Electronic speed-controlling devices had been used previously elsewhere but had met with strong resistance from the elite. In Brasília, resistance was minimized through the participation of the local media, which made the subject of traffic a priority. Correio Braziliense, which enjoys 90 per cent of the city's newspaper readership, published daily half-page traffic reports at no cost. The electronic speed-controlling devices were also installed and maintained at no cost by private companies, who received payment from the fines applied.

 

This program succeeded in creating a revolution in attitudes towards citizenship rights in traffic. This resulted in traffic speed reduction and respect for crosswalks, and a consequent reduction in traffic-related deaths. It created an innovative partnership between media, government and the public. This program acted in areas such as health, traffic, transportation, education, construction, finance and culture, and resulted in improved safety for cyclists and pedestrians. It has since been successfully copied in numerous other Brazilian cities, with significant decreases in traffic mortalities.

 

 

References and Resources for More Information

 

AARP (2009), Planning Complete Streets for an Aging America, American Association for Retired Persons Public Policy Institute (www.aarp.org/ppi); at www.aarp.org/research/housing-mobility/transportation/2009_02_streets.html.

 

Austroads (2014), Methods for Reducing Speeds on Rural Roads – Compendium of Good Practice, Report  AP-R449-14, Austroads (www.austroads.com.au); at www.onlinepublications.austroads.com.au/items/AP-R449-14.

 

Jan Willem Bolderdijk and Linda Steg (2011), Pay-As-You-Drive Vehicle Insurance As A Tool To Reduce Crash Risk: Results So Far And Further Potential, Discussion Paper No. 2011-23, Prepared for the Roundtable on Insurance Costs and Accident Risks, 22-23 September 2011, Paris, International Transport Forum (www.internationaltransportforum.org); at www.internationaltransportforum.org/jtrc/DiscussionPapers/DP201123.pdf.

 

CBO (2008), Effects of Gasoline Prices on Driving Behavior and Vehicle Markets, Congressional Budget Office (www.cbo.gov); at www.cbo.gov/ftpdocs/88xx/doc8893/01-14-GasolinePrices.pdf.

 

CMHC (2008), Taming the Flow — Better Traffic and Safer Neighbourhoods, Canadian Mortgage and Housing Corporation (www03.cmhc-schl.gc.ca); at http://publications.gc.ca/site/eng/9.564528/publication.html.

 

Joe Cortright (2017), Driving Faster Doesn’t Make You Happier: It Just Makes You Drive Farther, City Labs (www.citylab.com); at www.citylab.com/transportation/2017/03/driving-faster-doesnt-make-you-happier/520797.

 

Coulter Transportation Consulting (2004), Neighborhood Traffic Management in DuPage County: Recommended Actions, DuPage County Mayors and Managers Conference (www.dmmc-cog.org); at http://bit.ly/2usj8Kg.  

 

DEA (1999), Main Street…When a Highway Runs Through It, Transportation and Growth Management Program, Oregon DOT and Dept. of Environmental Quality (www.oregon.gov/LCD); at www.oregon.gov/LCD/TGM/docs/mainstreet.pdf.

 

DfT (2004), New Directions In Speed Management: A Review Of Policy, UK Department for Transport (www.dft.gov.uk); at http://bit.ly/2vxUAUl.  

 

Rune Elvik (2001), “Zero Killed in Traffic – from Vision to Implementation,” Nordic Road & Transport Research, No. 1 (www.vti.se/nordic/1-01mapp/toi1.htm).

 

Rune Elvik (2005), Speed and Road Safety: Synthesis Of Evidence From Evaluation Studies, Transportation Research Record 1908, TRB (www.trb.org), pp. 59-69; http://pubsindex.trb.org/view.aspx?id=762266.

 

FHWA, Traffic Calming Website (www.fhwa.dot.gov/environment/traffic_calming/index.cfm) by the Federal Highway Administration provides various resources for traffic calming planning.

 

FHWA, Speed Management Information Resources (http://safety.fhwa.dot.gov/speedmgt/ref_mats/fhwasa09028) by the Federal Highway Administration provides various resources for speed management.

 

Bill Frith (2012), Economic Evaluation Of The Impact Of Safe Speeds: Literature Review, Report 505, New Zealand Transportation Agency (www.nzta.govt.nz); at www.nzta.govt.nz/resources/research/reports/505/docs/505.pdf.

 

Per E. Gårder (2004), “The Impact of Speed and Other Variables on Pedestrian Safety in Maine,” Accident Analysis & Prevention, Volume 36, Issue 4 (www.elsevier.com/locate/aap), July, pp. 533-542.

 

GRSP (2008), Speed Management: A Road Safety Manual for Decision-Makers and Practitioners, Global Road Safety Partnership (www.grsproadsafety.org); at www.grsproadsafety.org/themes/default/pdfs/Speed%20management%20manual.pdf.

 

GHSA (2019), Speeding Away from Zero: Rethinking a Forgotten Traffic Safety Challenge, Governors’ Highway Safety Association (www.ghsa.org); at www.ghsa.org/sites/default/files/2019-01/FINAL_GHSASpeeding19.pdf.

 

Chris Grundy, et al. (2009), “Effect of 20 mph Traffic Speed Zones on Road Injuries in London, 1986-2006: Controlled Interrupted Time Series Analysis,” British Medical Journal, Vo. 339, b4469 (http://doi.org/10.1136/bmj.b4469).

 

IIHS (2000), Speed Law Enforcement  and Speed and Speed Limits (www.iihs.org/iihs/topics/t/speed/bibliography/bytag), Insurance Institute for Highway Safety (www.hwysafety.org).

 

IIHS (2003), IIHS Status Report, Special Issue: Speeding, Insurance Institute for Highway Safety (www.hwysafety.org).

 

ITF (2018), Speed and Crash Risk, International Transport Forum (www.itf-oecd.org); at www.itf-oecd.org/speed-crash-risk.

 

John N. Ivan, Norman W. Garrick and Gilbert Hanson (2009), Designing Roads that Guide Drivers to Choose Safer Speeds, Connecticut Transportation Institute, Connecticut Department of Transportation (www.ct.gov); at www.ct.gov/dot/LIB/dot/documents/dresearch/JHR_09-321_JH_04-6.pdf.

 

Peter L. Jacobsen, F. Racioppi and H. Rutter (2009), “Who Owns The Roads? How Motorised Traffic Discourages Walking And Bicycling,” Injury Prevention, Vol. 15, Issue 6, pp. 369-373; http://injuryprevention.bmj.com/content/15/6/369.full.html.

 

Ali Kamyb, et al (2003), “Methods for Reducing Traffic Speed in High-Pedestrian Rural Areas,” Transportation Research Record 1828, TRB (www.trb.org), pp. 31-37.

 

Dewan Masud Karim (2015), Narrower Lanes, Safer Streets, CITE Annual Conference; at http://bit.ly/1GKiICo.

 

Todd Litman and Steven Fitzroy (2005), Safe Travels: Evaluating Mobility Management Traffic Safety Impacts, VTPI (www.vtpi.org); at www.vtpi.org/safetrav.pdf.

 

Tracy McMillan and Jill Cooper (2019), Motor Vehicle Speed as a Risk Factor in Pedestrian Safety, Berkeley SAFETrec (https://safetrec.berkeley.edu); at https://bit.ly/2VN4uzM.

 

NACTO (2012), The Urban Street Design Guide, National Association of City Transportation Officials (www.nacto.org); at http://nacto.org/urbanstreetdesignguide-overview.

 

NACTO (2016), Global Street Design Guide, National Association of City Transportation Officials (www.nacto.org) and the Global Designing Cities Initiative (www.globaldesigningcities.org); at http://globaldesigningcities.org/publication/global-street-design-guide/streets/street-users.

 

National Highway Traffic Safety Administration (www.nhtsa.dot.gov) provides information on the risks of speeding, safety benefits of speed reductions, and recommendations for traffic speed reduction strategies, such as “Traffic Law Enforcement Programs” (www.nhtsa.dot.gov/people/injury/enforce).

 

OECD/ECMT (2006), Speed Management, Joint Transport Research Centre of the Organisation for Economic Co-operation and Development and the European Conference of Ministers of Transport (www.cemt.org/JTRC/WorkingGroups/SpeedManagement/index.htm).

 

Theodore A. Petritsch (2009), The Truth About Lane Widths, Pedestrian and Bicycle Information Center (www.walkinginfo.org); at www.walkinginfo.org/library/details.cfm?id=4348.

 

Carlos Felipe Pardo (2017), Reducing Speeds for Better Mobility and Quality of Life, UN Habitat (https://unhabitat.org); at https://unhabitat.org/reducing-speeds-for-better-mobility-and-quality-of-life-carlosfelipe-pardo.

 

Francesca Racioppi, Lars Eriksson, Claes Tingvall and Andres Villaveces (2004), Preventing Road Traffic Injury: A Public Health Perspective For Europe, World Health Organization, Regional Office for Europe (www.euro.who.int/document/E82659.pdf).

 

Donald A. Redelmeier and Ahmed M. Bayoumi (2010), “Time Lost by Driving Fast in the United States,” Medical Decision Making, Vol. 30, No. 3, pp. E12-E19; www.ncbi.nlm.nih.gov/pubmed/20190187?dopt=AbstractPlus.

 

Elihu D. Richter, Tamar Berman, Lee Friedman and Gerald Ben-David (2006), “Speed, Road Injury and Public Health,” Annual Review of Public Health, Vol. 27 (http://arjournals.annualreviews.org, April, pp. 125-152.

 

Tim Rowland and Deborah McLeod (2017), Travel Time Savings and Speed: Actual and Perceived, Report 568, New Zealand Transport Authority (www.nzta.govt.nz); at www.nzta.govt.nz/assets/resources/travel-time-savings-and-speed-actual-and-perceived/RR-568-Travel-time-savings-and-speed-actual-and-perceived.pdf.

 

SAHF (2012), Slow Motion: Why Reducing Speed Will Promote Walking And Cycling, South Australia Heart Foundation Active Living Coalition (www.saactivelivingcoalition.com.au); at http://saactivelivingcoalition.com.au/wp-content/uploads/2013/04/ReduceSpeedSnapshot_Feb13.pdf.

 

Angie Schmitt (2015), Compelling Evidence That Wider Lanes Make City Streets More Dangerous, StreetsBlog (http://usa.streetsblog.org); at http://bit.ly/1GKihYS.

 

The Slower Speeds Initiative (www.slower-speeds.org.uk) is an association of UK traffic safety organizations which works to investigate and promote traffic speed reduction activities.

 

Speed Management for Safety (https://bit.ly/2Cwo9Ix ) ITE website gives transportation professionals new tools for evaluating speed management and improving road design.

 

Jack Stuster and Coffman, Zail (1998), Synthesis of Safety Research Related to Speed and Speed Limits, FHWA-RD-98-154 Federal Highway Administration (www.fhwa.dot.gov); at www.tfhrc.gov/safety/speed/speed.htm.

 

Peter Swift (1998), Residential Street Typology and Injury Accident Frequency, Swift and Associates (www.sierraclub.org/sprawl/transportation/narrow.asp).

 

Peter Swift, Dan Painter and Matthew Goldstein (2006), Residential Street Typology and Injury Accident Frequency, Swift and Associates; at http://massengale.typepad.com/venustas/files/SwiftSafetyStudy.pdf.

 

M. Taylor, D. Lynam and A. Baruya (2000), The Effects Of Drivers Speed on the Frequency of Road Accidents, TRL Report 421, Transport Research Laboratory (www.trl.co.uk).

 

Paul Joseph Tranter (2010), “Speed Kills: The Complex Links Between Transport, Lack of Time and Urban Health,” Journal of Urban Health, Vol. 87, No. 2, doi:10.1007/s11524-009-9433-9; at www.springerlink.com/content/v5206257222v6h8v.

 

Vicky Feng Wei and Gord Lovegrove (2010), “Sustainable Road Safety: A New (?) Neighbourhood Road Pattern That Saves VRU (Vulnerable Road Users) Lives,” Accident Analysis & Prevention (www.sciencedirect.com/science/journal/00014575).

 

WHO (2004), World Report on Road Traffic Injury Prevention: Special Report for World Health Day on Road Safety, World Health Organization (www.who.int); at www.who.int/violence_injury_prevention/publications/road_traffic/world_report/en/index.html.

 

Charles V. Zegeer, Richard Stewart, Forrest Council and Timothy R. Neuman (1994), “Accident Relationships of Roadway Width on Low-Volume Roads,” Transportation Research Record 1445 (www.trb.org), pp. 160-168; complete report at http://onlinepubs.trb.org/Onlinepubs/nchrp/nchrp_rpt_362.pdf.

 

Charles Zegeer, et al (2002), Pedestrian Facilities User Guide: Providing Safety and Mobility, Pedestrian and Bicycle Information Center (www.walkinginfo.org), Highway Safety Research Center, Federal Highway Administration, Publication FHWA-RD-01-102; at www.fhwa.dot.gov/publications/research/safety/01102/01102.pdf.


This Encyclopedia is produced by the Victoria Transport Policy Institute to help improve understanding of Transportation Demand Management. It is an ongoing project. Please send us your comments and suggestions for improvement.

 

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