None of the of the five small crew cab pickups that recently underwent an updated moderate overlap front crash test rolled away with a good score.

Rather, three vehicles — the Chevrolet Colorado, Jeep Gladiator, and Toyota Tacoma — rated poor, the Ford Ranger earned a marginal rating, and the Nissan Frontier scored an acceptable rating.

The Insurance Institute for Highway Safety (IIHS) launched the updated evaluation last year after research found that in newer vehicles the likelihood of a fatal injury is now higher for belted occupants in the rear than for those in the front seat.

IIHS experts say that the latest tests pointed to a common problem among the crew cab pickups. Specifically, the rear passenger dummy's head came dangerously close to the front seatback, and in many cases, dummy measurements indicated a risk of neck or chest injuries. The bottom line is that rear seat belts need improvement, say IIHS experts.

The updated test adds a dummy in the back seat behind the driver. Ultimately, the goal is to motivate automakers to improve rear-seat protection. IIHS researchers also developed new metrics that focus on the injuries most frequently seen in back-seat passengers.

Here’s how the test works:

For a vehicle to earn a good rating, there can’t be an excessive risk of injury to the head, neck, chest, or thigh, as recorded by the second-row dummy. The dummy should remain correctly positioned during the crash without sliding forward beneath the lap belt. The head should also remain a safe distance from the front seatback and the rest of the vehicle interior.

While the five crew cab pickups tested provided solid protection in the front seat, there was a slightly higher risk of leg or foot injuries to the driver in the Gladiator and Tacoma. But it was the back seat where protection fell far too short for all five vehicles.

For example, in the Colorado, Frontier, Ranger, and Tacoma, the restraints in the back seat allowed the rear dummy’s head to come too close to the front seatback.

Meanwhile, the Gladiator exhibited a different problem. Its rear restraints do not include a side curtain airbag, increasing the risk of injury from a hard impact with the interior of the vehicle or even something outside it.

A second problem for the Ranger was the fact that the dummy slipped beneath the lap belt, causing it to ride up from the ideal position on the pelvis onto the abdomen, which increases the risk of internal injuries.

Finally, the crash evaluation indicated a moderate or likely risk of both neck and chest injuries in the poor-rated Colorado, Gladiator, and Tacoma and a moderate risk of chest injuries in the marginal-rated Ranger.