By JIM PARKER

The Post and Courier

Many vehicles are prepared these days to protect driver and front passenger in potentially tragic head-on collisions as well as jarring semi-direct hits.

But fewer are up to speed on guarding against glancing front-end blows, which — alarmingly — can be quite dangerous, according to the Insurance Institute for Highway Safety.

The safety research group’s 2009 study of vehicles with top-notch frontal crash protection found that one in four frontal crashes resulting in serious injury or death involved hits to no more than a side or edge of the front.

That’s a chief reason why the institute, which has been doling out car safety honors for six years, has added a “small overlap” frontal crash test to its vehicle safety rating criteria.

At the same time, the organization is bringing out a new accolade, the Top Safety Pick + award. The honor is for cars and trucks that handled the small overlap test as well as passed at least four other tests with flying colors.

This year, 13 vehicles earned the Top Safety Pick + award from nine car manufacturers.Two models are midsize luxury cars, while the other 11 are midsize moderately priced cars.

The institute has judged 29 vehicles in the small overlap test. SUVs and other trucks and models will be evaluated at a later date.

Of the models tested so far in small overlap crash simulation, “these 13 (top safety pick-plus) cars offer the highest level of all-around crash protection,” said Adrian Lund, the institute’s president. “We’re pleased to recognize them with our new award for 2013.”

Cars and trucks go through a rigorous grading system as part of the safety institute’s test.

The group rates vehicles on a four-grade scale — good, acceptable, marginal or poor. The ratings are based on the autos’ performance in a “moderate” overlap frontal crash, small overlap frontal crash, side impact and rollover. There are also evaluations of seat and head restraints for protection against neck injuries in rear impacts.

To earn the Top Safety Pick+ rating,cars must earn “good” scores in at least four of five evaluations. The fifth test can be no less than “acceptable.”

While the safety-plus list was rather small, the group of cars named a Top Safety Pick ( but not “plus”) was sizable at 117.

To qualify, vehicles had to post good ratings for occupant protection in the moderate overlap frontal test and side impact, rollover and rear tests, regardless of their small overlap rating.

“Models that earn Top Safety Pick also offer outstanding protection in many crashes,” Lund said. “These vehicles are much safer choices than most vehicles on the market just five years ago,” he said.

The organization introduced the small overlap test in 2012, it said, “to further improve occupant protection in frontal crashes.”

Luxury and near luxury midsize cars were the first groups tested, followed by midsize moderately priced cars, the institute said. The safety group plans to disclose additional Top Safety Pick+ winners as it continues to test models, noting that results for small SUVs are expected in the spring.

The small overlap test, according to the institute, “replicates what happens when the front corner of a car collides with another vehicle or an object like a tree or utility pole.”

Specifically, a “Hybrid III” test dummy representing a 50th percentile — or average sized — male is belted in the driver seat. In the test, 25 percent of a car’s front end on the driver side strikes a five-foot-tall rigid barrier at 40 mph.

A chief reason for the small overlap test stems from results of the institute’s study three years ago of vehicles with good ratings for frontal crash protection. “Small overlap crashes,” the group found, “accounted for nearly a quarter of the frontal crashes involving serious or fatal injury to front seat occupants.”

According to the institute, “Most automakers design their vehicles for good performance in the (group’s) moderate overlap frontal test and the federal government’s full-width frontal test, but many haven’t addressed the problem of small overlap crashes.”

The safety institute said it gives manufacturers advance notice of planned changes to the tests, and automakers in the past have been quick to factor new evaluations into their designs.

Car companies seem to be getting the picture on the latest test. “We’ve seen automakers make structural and restraint changes in response to our small overlap test,” Lund said. “Five manufacturers redesigned their midsize cars to enhance small overlap crash protection,” he said.

For instance, Honda engineered both versions of the Accord to handle the small overlap test, and Ford and Nissan made “running structural changes” to 2013 models already in production.

Subaru and Volkswagen, meanwhile readjusted airbag controls via the production line so side curtain airbags would deploy for improved head protection, the institute said.

The safety group said it has tightened criteria a couple of times since first giving out the Top Safety Pick award to 2006 models.

Rear test results of “good” and availability of electronic stability control were requirements starting with 2007 models. In the 2010 model year, a “good” roof strength rating became a deciding factor.

Stability control has been dropped as a distinguishing perk since it comes standard under federal rules for 2012 and later models.

Reach Jim Parker at 937-5542 or jparker@postandcourier.com.

TOP SAFETY PICK+ WINNERS:

• Acura TL midsize luxury car

• Volvo S60 midsize luxury car

• Dodge Avenger midsize moderately priced car

• Chrysler 200 four-door midsize moderately priced car

• Honda Accord two-door midsize moderately pricd car

• Honda Accord four-door misize moderately priced car

• Ford Fusion midsize moderately priced car

• Subaru Legacy midsize moderately priced car

• Subaru Outback midsize moderately priced car

• Kia Optima midsize moderately priced car

• Nissan Altima four-door midsize moderately priced car

• Suzuki Kizashi midsize moderately priced car

• Volkswagen Passat midsize moderately priced car.