Road traffic crashes and accidents claim 1.2 million lives and 10 million injuries worldwide every year.  More than a third of these numbers apply to pedestrians.  

How many of these fatalities and severe injuries are results of driver error, impaired driving or other unsafe driving practices, and how many are due to inherent vehicle safety, both mechanical and technological elements -- including brake systems, heavy wheels and unsuitable tires?

Vehicle safety regulation tends to focus on improving the level of protection a car provides its driver and occupants, but vehicles can also be designed to be safer for pedestrians.

Some studies and statistics exist regarding wheel sizing, wheel weight, and the pros and cons of “plus-sizing” (“plus-sizing” refers to, for example, changing a standard 16” diameter wheel for an 18” diameter wheel, which in this case entails a “Plus-2 Fitment”).

Although switching to bigger sized wheels, replacing the OE (original equipment) wheels and tires that are specifically designed and tested by car manufacturers is an attractive proposition for many drivers (big wheels can enhance a car’s appearance and handling and performance), it can also be dangerous if not done right --putting the drivers, their passengers and innocent pedestrians at greater risk.

A car’s suspension and brake system are engineered to perfectly operate with a certain amount of "unsprung weight" (mass of components not supported by the springs) -- the axles, wheels and tires, brakes, etc. Plus-sizing to heavier wheels puts more strain on the suspension system. That extra mass may cause various side effects for the vehicle, causing potentially longer stopping distance and even issues with steering control. It is possible to avoid most of these consequences with lighter forged wheels, but they are considerably more expensive.

In addition to having stringent rules and regulations enacted and enforced pertaining to plus-sizing wheels and tires, cars can be made safer for pedestrians by implementing other measures:

o   designing a vehicle’s front end, in terms of shape and structural stiffness, so that pedestrians and other road users are less likely to be injured if they at impact. According to the UK’s The Royal Society for the Prevention of Accidents (RoSPA), “the changes in the shape of many modern vehicle fronts, compared to older vehicles, has been influenced by pedestrian protection.” Design modifications can include increasing the crush depth between the outer surface of the vehicle and hard objects underneath (such as engine parts);

o   testing with crash dummies that replicate real-life pedestrian crashes, and involve vehicle deceleration and stopping distance rates, and force measurements; testing that includes factors like bumper heights and energy absorption, and front end spaces between the hood and engine components underneath;

o   shortening braking distance by way of a more robust high performance brake-system being installed at OEM level, and also reducing the weight of wheels, one of the advantages that forged wheels provide.

The world is becoming increasingly mobile. Autonomous vehicles are being developed. Many places are seeing populations aging. Governments must heed the technological advancements improving mechanisms that increase control over a vehicle and maximize braking capabilities to shorten the stopping distance. Even a small improvement can save numerous lives. Both the U.S. and the EU should lead in funding of continuous, extensive in-depth research aimed at enhancing the safety of vehicles. Upgrading automotive safety equipment and respective standards should be a prioritized reality. It is imperative that governing bodies enact and enforce the regulation upon manufacturers, as well as tuners, facilitating the safest possible vehicles to the motorists – thus ensuring greater safety for pedestrians.