A dangerous time to drive: 3 p.m. to 6 p.m.

It's interesting to note that in spite of the huge increase in traffic, the number of fatal road accidents per licensed driver is less than half of what it was 40 years ago, says the National Highway Traffic Safety Administration.

Death, however, still occurs every day on our streets and highways. The deadliest days to drive are Friday through Sunday, with Saturday coming out on top. There's more traffic on the weekend, and alcohol plays a role.

Rushing home from work after a stressful day takes its toll. The time between 3 p.m. and 6 p.m. is very dangerous. The most dangerous time to be on the road is around 2 a.m.

The good news is that the early morning rush hour seems to be safer than any other time of the day. Drivers are more alert.

For teenagers, the after-school hours between 3 p.m. and 5 p.m. are almost as dangerous as weekend nights, according to data from the American Automobile Association. On weekend nights, some 44 states limit driving by new drivers.

When you plan a holiday trip, keep traffic levels in mind. The days around Independence Day, July 4, are the most deadly of the year. December 23, is the third most deadly, and January 1 is in 5th position.

August 3, 4, 6, and 12 are also in the top ten most dangerous days. Many people are driving on vacations.

Braking versus downshifting

When going down a long hill in a car with an automatic transmission, should you brake or downshift to let the transmission slow the car?

Manually shifting to a lower gear during a long descent makes sense. It allows the engine's resistance to control the car's speed. That's true on both automatic and manual transmissions. 

Some pickup trucks and trucks used for towing now have automatic transmissions with "logic" that sense hilly terrain. They hold the car in a lower gear for longer periods. 

Don't downshift unless you are going down a long steep hill. Frequent manual downshifting can increase automatic transmission wear. 

While a brake job costs about $300, transmission repairs can cost $1,000 or more.

Failure to buckle up is still
the biggest factor in vehicle deaths

Recent statements by the top auto-safety regulator angered some auto industry executives. Jeffrey W. Runge, head of the National Highway Traffic Safety Administration, spoke about the high centers of gravity and poor rollover safety scores on some sport utility vehicles.

Runge made an even more significant point: 72 percent of those who die in light-truck rollovers aren't wearing seat belts.

The main reason people get killed in rollover accidents is that they get thrown out when the pickup or SUV rolls. Chances of staying in the cab are much better if you are wearing your belt.

It's only since about 1990 that the majority of American drivers have been buckling up, says Dr. Runge, formerly an emergency-room physician. In 1983, only 14 percent of us wore seat belts. In 1990, the rate had risen to 49 percent. As mandatory seat-belt laws came into effect, the usage rate went up to 75 percent in 2002. Note that in Europe usage rates are about 90 percent.

Dr. Runge says that if 90 percent of Americans wore seat belts, 6,600 lives per year would be saved and 140,000 injuries would be prevented, saving society more than $26 billion annually.

Advanced safety technology won't deliver the maximum benefit unless those in the car are wearing seat belts.

Jay Cooney, director of safety communications at General Motors Corp., said the major reason for fatalities in rollovers is a lack of seat-belt use.