We’ve come a long way from the “unsafe at any speed” car-manufacturing era of the 1960s. Cars today are safer than they were even a few years ago, with blind-spot detection and lane-departure warning systems available to help drivers avoid collisions.

And these days you can easily research the safety of just about any vehicle on the market using safercar.gov, from the government’s National Highway Traffic Safety Administration (NHTSA), or the independent, nonprofit Insurance Institute for Highway Safety (IIHA) — or both. The NHTSA’s YouTube channel, SaferCarTV, even lets you watch crash test videos in slow motion. You can also view crash and safety tests on the IISH’s YouTube channel.

The two groups have different rating systems and different measures to help you understand what might happen to you and your passengers in a variety of accidents. Here’s what you can learn from each.

National Highway Traffic Safety Administration

The NHTSA tests for frontal crashes, side crashes and rollover risk. It rates cars using a five-star system, five being safest. It also recommends advanced safety technology by model.

In the five-star system, the number of stars suggests your risk of injury in each scenario tested. A five means the risk of injury is much less than average; a four means less-than-average to average; and anything three and lower suggest average risk down to much greater than average risk.

Car shoppers can research their chosen make, model and year online or at the dealership, where five-star ratings are posted on new vehicle window stickers. In 2011 the NHTSA changed its ratings criteria to reflect additional testing and data in order to better discriminate among ever-safer cars. It now takes into account the results of side pole testing (which mimics crashing into a pole), the use of different-size crash test dummies (representing males and females) and the presence of crash-avoidance technologies. It also added an overall vehicle score.

The NHTSA also rates tires for safety performance and provides access to a recall database that you can search by vehicle identification number (VIN). You can find the VIN of your car on the dashboard under the windshield glass on the driver’s side, visible from outside the car. It is also on the title of your car and your car insurance policy documents.

Insurance Institute for Highway Safety

The institute ranks cars as good, acceptable, marginal or poor based on performance in five categories: front crashes with moderate overlap (when a good portion of the front of the car hits an object), front crashes with small overlap (when the front corner of the car hits an object), side crashes, roof strength and head restraints. The IIHS does not test for rollover risk. 

It also looks at crash avoidance and mitigation (technology that can help the driver avoid a crash or reduce the severity of a crash).

The various ratings are used to produce an annual list of vehicles by size and type. Some are given the ranking of Top Safety Pick (TSP) or Top Safety Pick+ (TSP+). You can research cars by make, model and year, or use the TSP list if you are trying to choose a car based largely on relative safety.

A Top Safety Pick vehicle earned good ratings on moderate-overlap front and side crashes and on roof strength and head restraint tests, as well as a good or acceptable rating in the small-overlap front crash test. The plus symbol (+) means the vehicle also features at least the basic front crash prevention technologies, including an automatic braking system that stops the car if it heading for a collision.

Chances are, whatever vehicle you choose will be safer than the old clunker you’re trading in or passing down. (In fact, that’s why some experts recommend you let your newly licensed teen drive the newer car.) But why not make it the safest choice possible?

Greg writes about personal finance, business and technology. His work has appeared in Businessweek, Newsweek, Forbes, Bankrate and a variety of trade ​publications.