The basic problem of truck underride is the fact that there is a geometric mismatch between the large trucks and the smaller passenger vehicles. Crush zones are structural areas in a vehicle that are designed to absorb energy upon impact in a predictable way. However, upon collision of a passenger vehicle with a truck, there is no opportunity for engagement of the passenger vehicle crush/crumple zone with a solid portion of the truck.

The result? The crashworthiness of the passenger vehicle is not initiated. The car is allowed to go under the truck and the first point of impact is in the Passenger Occupant Space. The passengers are left vulnerable to horrific injuries and violent deaths.

In fact, although underride deaths are vastly underreported and undercounted, FARS data from the NHTSA show that hundreds of people die every year from truck underride passenger compartment intrusion (PCI). NHTSA reported 4,006 underride deaths from 1994 to 2014.

The rear underride guards, which are installed on semi-trailers, are supposed to prevent underride. But the IIHS, in 2011 and 2013, conducted crash testing which proved that the guards of eight major trailer manufacturers, though designed the meet the 1998 federal standard, too often fail. Subsequently, improved rear underride guards and side guards have been crash tested by the IIHS; crash dummies emerge with survivable results.

The majority of the large trucks on the road either have weak, ineffective rear underride guards – even though they meet the current federal standard – or none at all (as in the case of exempt single-unit trucks) or improperly maintained rear guards (initially known as ICC bumpers, later as Mansfield bars, or sometimes as Rear Impact Guards or RIGs). In addition, there is currently no federal requirement for commercial motor vehicles to have side guards – despite the fact that there is normally 4 feet between the bottom of the trailer and the road. And, although Europe has standards for Front Underrun Protection, the U.S. does not.

There were 340,000 large trucks manufactured in 2015. The majority of those have weak rear guards and no side guards. Volvo Trucks produces tractors with front underride protection in Europe but not on their North American trucks. There are nearly 2 million semi trucks in operation in the U.S. and around 5.6 million semi trailers. These drive around every day on our roads putting travelers at risk of Death by Underride.

The truck industry has known about the problem of underride for over a century. In fact, a patent was filed for a side guard in 1913. In response to the rear underride death of actress Jayne Mansfield in 1967, we saw some improvement in rear underride protection with a 1998 standard – although you will notice that that took 31 years to achieve and it still falls short of what is technologically possible some 50 years after her death.

The government is also well aware of the side underride problem. On March 19, 1969, the FHWA indicated in the Federal Register, in an analysis on rear underride rulemaking, that they intended to extend underride protection to the sides of large trucks after further studies. However, DOT has not done so and the industry – despite some voluntary improvement in response to appeals from victim families armed with information on the IIHS crash testing – has not shown an ability or willingness to solve this problem on their own.

As David Ward recently said, at the Road to Zero Coalition October 2017 quarterly meeting, there will always be a strong need for regulation and/or fiscal incentives to break market failure. Only then will we see 100% adoption of comprehensive underride protection. In fact, trailer manufacturers have said that a mandate would lift the burden from them; they would no longer have to persuade their customers to buy safer trailers.

The underride problem has been documented in numerous studies. The IIHS petitioned NHTSA in 2011 and the NTSB made recommendations in April 2014 that NHTSA initiate underride rulemaking to address safety vulnerabilities. The Volpe National Transportation Systems Center has recognized the problem and has worked with numerous Vision Zero Cities to install side guards on city trucks in order to protect Vulnerable Road Users.

A comprehensive underride protection rule, STOP Underrides! — because it will include single-unit trucks — will make it easier for cities throughout the U.S. to protect vulnerable road users. Every truck that drives on their streets will be equipped with comprehensive underride protection – a significant victory in the battle to create safer mobility for pedestrians, cyclists, and motorcyclists, as well as passenger vehicles.

With comprehensive underride protection installed on the entire large truck fleet, we should see a significant decrease in the 4,000 truck crash fatalities/year (4,713 in 2016), along with a major reduction in debilitating injuries. Truck crashes can be made more survivable.

Or do we want to continue to allow people to die?