Pedestrians and bicyclists

Pedestrian deaths have increased 45 percent since reaching their low point in 2009 and account for 16 percent of crash fatalities. Two percent of people killed in motor vehicle crashes are bicyclists.

Traffic engineering improvements can reduce pedestrian and bicyclist crashes. Separating vehicles and pedestrians by installing sidewalks, overpasses and underpasses can help reduce conflicts. Other solutions include building median islands and adjusting traffic signals to create an exclusive pedestrian or bicyclist phase or to give them a head start before vehicles get a green light. Lowering vehicle speeds can also reduce injury severity for pedestrians and bicyclists involved in crashes.

Crash avoidance features and other vehicle improvements may also make pedestrians and bicyclists safer. Forward collision avoidance systems are increasingly designed to detect pedestrians in a vehicle's path, and rear cameras may prevent backover crashes. Modifying the front structures of vehicles may reduce the severity of pedestrian injuries. Regulators in Europe and elsewhere have been encouraging pedestrian protection in vehicle design through their vehicle testing programs.

Helmets provide critical protection for bicyclists. Among a majority of bicyclists killed in crashes, head injuries are the most serious injuries. Helmet use has been estimated to reduce the odds of head injury by 50 percent.

There were 5,977 pedestrians and 777 bicyclists killed in 2017 and approximately 73,000 pedestrians and 54,000 bicyclists injured in motor vehicle crashes on public roadways in the United States. Pedestrians comprised about 16 percent of crash deaths, and bicyclists made up an additional 2 percent.

In a majority of bicyclist deaths, the most serious injuries are to the head, highlighting the importance of wearing a bicycle helmet (Sacks et al., 1991). Helmet use has been estimated to reduce the odds of head injury by 50 percent, and the odds of head, face or neck injury by 33 percent (Elvik, 2013).

Twenty-one states and the District of Columbia have helmet use laws applying to young bicyclists. None of these laws apply to all riders. Local ordinances in a few states require some or all bicyclists to wear helmets.

The odds that a bicyclist will wear a helmet are 4 times higher after a helmet law is enacted than before a law is passed (Karkhaneh et al., 2006).  Helmets are important for riders of all ages, not just young bicyclists. Eighty-six percent of fatally injured bicyclists in 2017 were age 20 or older. During the past few years, no more than 17 percent of fatally injured bicyclists were wearing helmets.

Helmet use rates are lower among bike share users than among riders of personally-owned bicycles, even in cities requiring helmet use for all ages (Fischer et al., 2012; Zanotto & Winters, 2017).

Not all helmets provide the same reduction in concussion risk (Bland et al., 2018). A bicycle helmet ratings program at Virginia Tech, based on research performed in collaboration with IIHS, ranks helmets on their performance in impact tests.

Higher vehicle speeds increase the risk of crash involvement and the risk of injury or death when a crash occurs. Because pedestrians and bicyclists don't have a vehicle's structure to protect them, small increases in vehicle speeds have an especially large impact on the risk of a serious injury or fatality. In a study of U.S. pedestrian crashes, the average risk of severe injury to a pedestrian increased from 10 percent at an impact speed of 17 mph to 25 percent at 25 mph, 50 percent at 33 mph, 75 percent at 41 mph, and 90 percent at 48 mph (Tefft, 2013).

Effective engineering measures to reduce speeds in urban areas include traffic calming devices such as speed humps and multiway stop signs (Retting et al., 2003;  Rothman et al., 2015). Lowering speed limits on city streets reduces the proportion of vehicles traveling at high speeds and has potential to prevent pedestrian and bicyclist injuries (Hu & Cicchino, 2019).

Some design strategies to protect pedestrians and bicyclists from crashes, such as sidewalks and bike lanes, separate them from motor vehicles. Sidewalks in residential areas are highly effective (Retting et al., 2003).

The effects of countermeasures that separate bicycles from traffic are less clear. Some studies have found bicycle lanes to be associated with reductions in crashes and injuries, while others have reported no changes or increases (DiGioia et al., 2017).

Protected bike lanes, also called cycle tracks, are physically separated from traffic with barriers such as posts or parked cars. Two Canadian studies concluded that injury risk is lower for bicyclists in protected bike lanes compared with riding in the road (Teschke et al., 2012; Lusk et al., 2011), but protected lanes have not been rigorously evaluated in the United States.

An evaluation in Copenhagen of protected bike lanes that allowed use by bicycles and mopeds reported that the frequency of some crash types, such as cars rear-ending bicycles or mopeds, decreased after protected bike lanes were built, but that others, such as collisions of bicycles or mopeds with pedestrians or turning vehicles (Jensen, 2008), increased.

Pedestrians and bicyclists can be separated from traffic as they cross the street by overpasses, underpasses, and median islands in busy two-way streets (Retting et al., 2003).

Effective countermeasures involving changes to traffic signals include exclusive traffic signal phasing that stops all vehicle traffic for part or all of the pedestrian or cyclist crossing signal duration, and left turn phasing, in which left-turning vehicles have a green arrow and crossing pedestrians or cyclists have a red light (Retting et al., 2003; Chen et al., 2013; Ledezma-Navarro et al., 2018).

Extending the time available for pedestrians to cross at intersections with signals can be beneficial, especially for older pedestrians (Chen et al., 2013; Stollof et al., 2007).

Providing pedestrians a three- or four-second head start through a leading pedestrian interval (a signal that allows pedestrians to begin crossing before the release of turning vehicles) has been found to increase the percentage of left-turning vehicles that yield to pedestrians and reduce conflicts between pedestrians and turning vehicles and pedestrian crashes (Chen et al., 2013; Van Houten et al., 2000; Pécheux et al., 2009).

In a study conducted over a 10-year period in Detroit, pedestrian countdown signals, which show the amount of time remaining to cross the street with the green light, were associated with reductions in crashes with pedestrians (Huitema et al., 2014).

Special warning signs and pavement markings to encourage or prompt pedestrians to look for turning vehicles as they cross the street may help at signalized intersections (Retting et al., 1996).

Pedestrian hybrid beacons make pedestrians more visible to motorists by alerting drivers to stop at crosswalks across major arterials when pedestrians are present. The signals are activated by pedestrians and remain dark when there are no pedestrians. In a 2009 study, pedestrian hybrid beacons were associated with a 59 percent reduction in pedestrian crashes (Fitzpatrick & Park, 2009). Although the effects on cyclists have not been tested, pedestrian hybrid beacons have potential to benefit crossing cyclists as well as pedestrians.

Rapid-flashing beacons, which are yellow LEDs mounted to pedestrian or bicyclist crossing signs that flash in an irregular pattern when non-motorists are present, also draw the attention of drivers to pedestrians and cyclists and have been shown to increase the percentage of drivers that yield to them in crosswalks (Hunter et al., 2012).

Bike boxes, also called advanced stop lines or advanced stop boxes, are designated areas for bicyclists to stop in front of queued traffic at red lights. They have been shown to reduce conflicts with vehicles at signalized intersections (Dill et al., 2012).

Most struck pedestrians and bicyclists are hit by the front of a passenger vehicle. What happens next depends on a number of factors including the speed of the vehicle and the relative heights of the pedestrian or bicyclist, the front end of the vehicle and the bumper.

For pedestrians struck by cars, the initial contacts are with the vehicle bumper and/or the front edge of the hood. When pedestrians are struck by taller vehicles such as SUVs or pickup trucks, the impact is higher on the body (Crandall et al., 2002). Typically, larger vehicles mean more serious injuries and higher risk of death (Roudsari et al., 2004).

In the study of pedestrian crashes between 2009 and 2016, IIHS researchers found that fatal single-vehicle crashes involving SUVs increased 81 percent, more than other type of vehicle (Hu & Chcchino, 2018).

Vehicle design can influence the type and severity of pedestrian injuries. Modifying the front structures of passenger vehicles to reduce the severity of pedestrian injuries has been the subject of research for decades (Ashton & Mackay, 1983; United Nations Economic Commission for Europe, 2009; Daniel, 1982).

As a result of this research, regulators in Europe, Japan, Korea and Australia have implemented vehicle testing programs specifically aimed at protecting pedestrians. These testing programs focus on pedestrian interaction with the hood and bumper and in some cases the hood edge and the windshield. EuroNCAP has plans to introduce testing of vehicle front ends that will also address bicyclist injuries.

To perform well in these tests, automakers have been putting more room between the hood and engine, designing pop-up hoods that automatically lift up a few inches upon impact, adding pedestrian hood airbags that cover the parts of the windshield and A-pillar where pedestrians frequently hit their heads, and designing bumpers with more give (Strandroth et al., 2014).

Institute researchers conducted a series of head impact tests mimicking those used internationally with seven 2002-07 model small cars. Using data from police-reported crashes in 14 states, the researchers found that these tests were good predictors of pedestrian injury and fatality rates (Muelller et al., 2013).

A complementary study looked at leg impact tests on the same vehicles and found no correlation between test results and injury rates because bumper designs on all of the vehicles performed poorly (Mueller & Nolan, 2017).

The U.S. government is currently considering whether to adopt a pedestrian protection vehicle testing program similar to that used in Europe (Office of the Federal Register, 2015).

Pedestrian detection systems continuously monitor traffic in front of vehicles and warn drivers of potential collisions with pedestrians. Many systems automatically apply the brakes when a crash is imminent. Systems are being developed to prevent or mitigate crashes with cyclists as well.

An Institute analysis estimated that pedestrian crash prevention systems could potentially mitigate or prevent up to 65 percent of single-vehicle crashes with pedestrians in the three most common crash configurations and 58 percent of pedestrian deaths in these crashes (Jermakian & Zuby, 2011). Cyclist crash prevention systems were estimated to potentially mitigate or prevent up to 47 percent of crashes with bicyclists and 54 percent of bicyclist fatalities in five common crash configurations (MacAlister & Zuby, 2015). However, their real-world effectiveness depends on how they function at high speeds or in low light, situations that account for the majority of pedestrian and bicyclist deaths.

The Institute began rating pedestrian crash prevention systems in 2019.

The Highway Loss Data Institute studied insurance claim rates for Subaru models with and without the optional EyeSight system, a crash avoidance system with pedestrian-detection capability (HLDI, 2017). Pedestrian injury claim rates were 35 percent lower among vehicles with EyeSight than among vehicles without. Claims were assumed to be from pedestrian crashes if they involved a bodily injury liability claim without a claim for vehicle damage.

Rearview cameras have been shown to prevent backing crashes with pedestrians (Keall et al., 2017), and could potentially prevent such crashes with bicyclists.

A vehicle's sound helps pedestrians, especially those who are visually impaired, detect a vehicle's presence and movements. Electric vehicles emit less sound than vehicles with combustion engines. The same is true of hybrid vehicles when powered solely by electricity.

A government study examined the crashes of hybrid vehicles and similar nonhybrid vehicles and found that the likelihood of crashing with a pedestrian was 39 percent higher for hybrids than for nonhybrids in areas where speed limits were 35 mph or slower and 66 percent higher when performing certain maneuvers such as turning, stopping and backing up (Wu et al., 2011). These maneuvers typically occur at very low speeds, when hybrids operate mostly on electric power.

In a study of insurance claims for 2002-10 hybrid models and their conventional twins, the Highway Loss Data Institute found that hybrids were as much as 20 percent more likely to be involved in pedestrian crashes with injuries than their non-hybrid equivalents (HLDI, 2011). Claims were assumed to stem from a pedestrian crash if they involved an injury liability claim without a claim for vehicle damage. 

New hybrid and electric vehicles will be required to emit a motor-like sound while moving forward or in reverse at speeds up to 19 mph by September 1, 2020 (Office of the Federal Register. 2018).

Adding an hour of light to the afternoon increases the visibility of both vehicles and pedestrians, and Institute research has found that implementing daylight saving time year round could help prevent pedestrian deaths and injuries (Ferguson et al., 1995).

IIHS researchers estimated that about 900 fatal crashes (727 involving pedestrians and 174 involving vehicle occupants) could have been avoided during 1987-91 if daylight saving time had been in effect throughout the year.