A few months ago, in response to the Raquel Nelson case, author Tom Vanderbilt found an FHWA study from 2005 that finds that on wide, busy roads, pedestrian death rates are higher on marked crosswalks than on unmarked ones. The study itself is worth reading; its explanation of the finding is that,
These results may be somewhat expected. Wide, multilane streets are difficult for many pedestrians to cross, particularly if there is an insufficient number of adequate gaps in traffic due to heavy traffic volume and high vehicle speed. Furthermore, while marked crosswalks in themselves may not increase measurable unsafe pedestrian or motorist behavior (based on the Knoblauch et al. and Knoblauch and Raymond studies) one possible explanation is that installing a marked crosswalk may increase the number of at-risk pedestrians (particularly children and older adults) who choose to cross at the uncontrolled location instead of at the nearest traffic signal.
An even greater percentage of older adults (81.3 percent) and young children (76.0 percent) chose to cross in marked crosswalks on multilane roads compared to two-lane roads. Thus, installing a marked crosswalk at an already undesirable crossing location (e.g., wide, high-volume street) may increase the chance of a pedestrian crash occurring at such a site if a few at-risk pedestrians are encouraged to cross where other adequate crossing facilities are not provided. This explanation might be evidenced by the many calls to traffic engineers from citizens who state, “Please install a marked crosswalk so that we can cross the dangerous street near our house.” Unfortunately, simply installing a marked crosswalk without other more substantial crossing facilities often does not result in the majority of motorists stopping and yielding to pedestrians, contrary to the expectations of many pedestrians.
This is a rather standard application of Smeed’s law and similar rules governing traffic, whose one-line form is that traffic fatalities are determined primarily by psychology. This is not a problem; the problem is why such issues are only ever brought up in case of pedestrian fatalities.
In 1949, R. J. Smeed found a simple explanation for traffic fatalities: they depend less-than-linearly on the number of cars on the road. In the 1980s John Adams revised this to a more accurate rule based on VMT rather than the number of cars, and based on a constant decline in per-VMT accidents over time. Safety improvements do not bend or break the general trend. Quoting Adams again, the introduction of seat belts caused no reduction in traffic fatalities, and on the contrary caused pedestrian fatalities to temporarily inch up, as drivers felt safer and drove more recklessly. The only way to reduce the number of car accident victims is to reduce traffic.
And yet, government reaction is consistently on the side of accepting Smeed’s law when it implies there’s no need to improve pedestrian facilities, and rejecting it when its implication is bad for cars or good for pedestrians and cyclists. Local governments in the US routinely argue that safety is at stake when they want to upgrade a road with grade crossings into a full freeway. The FHWA helpfully adds that intersections are responsible to half of all car crashes and “FHWA will identify the most common and severe problems and compile information on the applications and design of innovative infrastructure configurations and treatments.”
In reality, all building freeways does is create more traffic, and cause more people to die in crashes. The average per-VMT death rate in the US has declined by 3.3% per year, but in the years following the Interstate Highway Act, it was practically flat – in other words, building freeways did nothing to accelerate the trend for reduction in per-VMT accident deaths. Although an individual freeway is undoubtedly safer than an individual road with intersections, the road network has to be viewed as a system: increase safety in one area and people will drive more recklessly elsewhere.
This systemwide view is clearly present in the case of pedestrians: the FHWA isn’t claiming that crosswalks are inherently unsafe, only that they cause more at-risk pedestrians to cross. In other words, the problem is that they cause too many of the wrong kind of pedestrians to cross. The implication is never used for roads. Traffic is never treated as variable, and if people shoot down freeway upgrades on the grounds that they’ll induce more traffic, it’s always on environmental or community grounds rather than on safety grounds.