Automakers are delivering major improvements in their automatic emergency braking systems following the introduction of a tougher front crash prevention evaluation by the Insurance Institute for Highway Safety (IIHS) last year.

“The rapid progress manufacturers have made to improve these vital crash avoidance systems is impressive,” IIHS President David Harkey said. “Vehicles that excel in this new test will save lives, as it addresses the most dangerous kinds of front-to-rear crashes.”

Twenty-two of the latest 30 vehicles evaluated earned a good or acceptable rating, which requires systems to be able to prevent or substantially mitigate crashes at higher speeds. A year ago, only three out of the first 10 small SUVs tested performed to that level.

The original vehicle-to-vehicle front crash prevention test was run at 12 and 25 mph with a passenger car target in the center of the travel lane. The updated test includes trials run at 31, 37 and 43 mph. In addition to a passenger car target, it examines performance with a motorcycle target and a semitrailer. Vehicles are tested with the semitrailer centered in the travel lane and with the car and motorcycle targets centered and offset to one side.

The systems rated good delivered timely forward collision warnings and came to a complete stop before impact in all the trials with the passenger car target. They also met those performance standards in most trials with the motorcycle target and provided timely warnings in all the trials with the semitrailer.

A few vehicles didn’t manage to stop before hitting the target in one or more of the motorcycle test scenarios, although they slowed substantially before impact. For vehicles that didn’t rate as well, the motorcycle tests were the most common stumbling block.

Overall, the systems rated acceptable brought the equipped vehicles to a complete stop before impact and delivered timely warnings in a large majority of the trials. However, their performance was subpar at higher speeds, especially with the motorcycle target. They all failed to prevent a collision with the motorcycle target in the 43 mph test scenarios. In some cases, they hit the target at speeds of more than 25 mph.

All the vehicles rated poor hit the motorcycle target in the slowest, 31 mph, test. The poor-rated vehicles also struggled in the tests with the passenger car target. “These results indicate that preventing crashes at higher speeds, especially collisions with motorcycles, remains a challenge for some systems,” Harkey said. “Motorcycles are a special area of concern because riders have little protection from crash injuries.”

The Acura ZDX, BMW X5, BMW X6, Cadillac Lyriq, Chevrolet Blazer EV, Genesis GV80, Honda Prologue, Hyundai Santa Fe, Kia EV9, Kia Sorento, Lexus NX, Subaru Forester, Toyota Camry, Toyota Crown Signia and Toyota Tacoma all earned good ratings for their standard systems. The Mercedes-Benz E-Class is available with an optional system that also earned a good rating.

The Ford Expedition earned a marginal rating. The Audi Q7, Audi Q8, Buick Envista, Chevrolet Tahoe, Chevrolet Trax, Kia Seltos and Nissan Altima are rated poor.