According to the National Highway Traffic Safety Administration (NHTSA), tires can lose up to half their air pressure before they actually appear to casual observers to be underinflated. Tire failure due to underinflation affects your driving safety in two basic ways:
- Integrity of the tire: Tire pressure literally changes the way the rubber meets the road, affecting traction, handling, steering, stability and braking.
- Uneven tread wear: Worn tire tread not only affects traction and handling, but also puts you at risk for blowouts–a potentially extremely dangerous event to experience while driving.
Because 75% of roadside flats are preceded by a slow leak or underinflation (www.safecar.gov), it's also important to consider what to do if and when a flat tire occurs. Will it be on a remote highway? At nighttime? In the middle of a busy intersection? In any case, the single best way to avoid the inconvenience, cost, vulnerability and risk of sudden tire failure is to maintain your tire pressure.
In France, the Sécurité Routière, a road safety organization, estimates that 9% of all road accidents involving fatalities are due to a tire under-inflation. In Germany the DEKRA, estimated that around 41% of accidents with physical injuries are linked to tire problems.
That's why checking your tire pressure regularly is so important. And that's how a tire pressure monitoring system (TPMS) positively affects motorists, by automatically alerting them when sensors detect a tire to be underinflated by 25% or more below the placard tire pressure for the vehicle.
A tire can lose air pressure without appearing to be underinflated.
To see how little difference there is in appearance between a properly inflated and an underinflated tire, use this Interactive Tire Pressure Demo on NHTSA's safercar.gov Web site.
Seeing Is Believing
Bridgestone® filmed the distinct difference in sudden avoidance maneuvers while driving on both properly inflated and underinflated tires.