When you walk into a Washington D.C. metro area car dealer’s showroom, salespeople will tell you with considerable enthusiasm about their vehicles’ safety features. Typically prominent in those discussions are a pair of coveted ratings from the Insurance Institute for Highway Safety (IIHS): Top Safety Pick+ and Top Safety Pick.

The IIHS’s annual tests determine how well vehicles will withstand, mitigate and avoid motor vehicle accidents.

While nearly everyone who has shopped for a new vehicle has seen the IIHS ratings, it might not be clear what kinds of tests the organization performs and what the tests mean.

Let’s take a look.

What is the IIHS?

Originally formed in 1959 by insurance companies that wanted to promote road safety, the organization is today an independent nonprofit that does its own crash prevention research.

The IIHS does a variety of vehicle safety tests, including front crash prevention, as well as tests of seats, roofs, side airbags, headlights and so on.

Dissecting IIHS ratings

In order for a vehicle to get an IIHS Top Safety pick rating, a 2020 vehicle must receive a rating of Good in all crash tests, and it must receive an Advanced or Superior rating for its systems to prevent or mitigate vehicle crashes and pedestrian collisions. It must also have headlights rated Acceptable or Good available as an option.

In order for a vehicle to get a Top Safety Pick+ rating, it must have all of the above ratings, but Acceptable or Good headlights must be standard features.

IIHS crash tests

The six crash assessments the IIHS performs include three frontal crash tests, a roof strength test, side crash test and a test of head restraints and seats.

Moderate overlap frontal test

With a crash test dummy in the driver’s seat, the vehicle is slammed into a barrier that has 40 percent of the vehicle’s width to simulate a front-end collision between two vehicles, each traveling at 40 mph.

Driver-side and passenger-side small overlap frontal test

In this test, the vehicle is rammed into a barrier that has 25 percent of its width in order to create a crash similar to one in which a vehicle strikes a utility pole or tree.

The three overlap tests enable assessments of whether a vehicle’s crash-energy-absorbing crumple zones and safety cage allow a wheel or other component to enter the vehicle’s cabin and cause injuries.

Side crash

In this test, a 3,300-pound barrier hits the vehicle’s driver-side at 31 mph to assess passenger safety, including head protection and the performance of the vehicle’s safety cage.

Head restraints and seats

In this test, a crash dummy and sled are used to measure the effectiveness of seats and head restraints in preventing neck injuries in rear-impact collisions.

Roof strength

To assess the structural integrity and passenger-protection afforded in a rollover by a vehicle’s roof, a metal plate is slammed into the roof.

Other IIHS tests

According to a recent news article, the organization also tests crash avoidance tech offered in some vehicles, including front-collision warning and automatic emergency braking systems.

The IIHS also conducts rigorous tests of headlights and LATCH (Lower Anchors and Tethers for Children) systems to arrive at its Top Safety Pick and Top Safety Pick+ ratings.

The organization’s safety assessments might well be an important part of the decision-making process the next time you’re shopping for a vehicle.