Plenty of truckers have found themselves forced by their schedules to travel through a large urban area during rush hour, caught in a sea of cars in what some describe as “killer traffic.” Well, it turns out that term is not inappropriate.

Two recent studies have shown that stress from heavy traffic can actually lead to a far higher risk of heart attack or other circulatory problems.

A Harris Interactive survey sponsored by Biovail Pharmaceuticals Inc. concluded that more than half of Americans experience enough stress in traffic to increase the risk of a heart attack or stroke.

“A stressful commute coupled with high blood pressure may be a dangerous combination,” Dr. Karol E. Watson of UCLA said in a statement.

The study notes that most Americans commute during the period from 6 a.m. to noon everyday – coincidentally, the hours during which strokes and heart attacks are most common.

The problem is particularly bad for those drivers who get angry over the antics of others on the road.

“People who are easily enraged are three times more likely to have a serious cardiovascular event than are those who respond to stress without anger,” Watson said.

Another study, this one published in The New England Journal of Medicine, studied traffic in Germany.

That study specifically found an association between exposure to trafficand myocardial infarctions – heart attacks – within one hour after being in heavy traffic. That study found that the amount of time people spent in their vehicles “was consistentlylinked with an increase in the risk of myocardial infarction.”

The authors of the Harris study suggested several ways people can reduce the risk of a heart attack or stroke caused by traffic-induced stress. Among those suggestions are:

• Travel during off-peak times to avoid rush-hour traffic tie-ups;
• Listen to local traffic reports and take alternate routes through grid-locked areas;
• Listen to calming music or a book on tape;
• Ask your doctor if your blood-pressure medication will protect you during the risky morning hours; and
• Exercise regularly.