SEATTLE Some are saying it was bound to happen, thanks to the growing popularity of GPS devices.

A charter coach ran into a pedestrian bridge apparently because the driver was paying attention to his GPS navigation device that routed his bus under a nine-foot bridge, and not to the warning signs along the road.

The crash sent 21 passengers, a high school girls softball team, to the hospital.

Steve Abegg, president of Journey Lines in Lynnwood, Wash., told a Seattle newspaper the off-the-shelf GRS navigation unit being used by the driver had settings for car, motorcycle, bus or truck.

Although the unit was set for a bus, it chose a route through Washington Park Arboretum that did not provide enough clearance for the 12-foot coach. The driver told police he did not see the flashing lights or yellow sign posting the bridge height.

"We just thought it would be a safe route, because why else would they have a selection for a bus?" Abegg said of the GPS unit.

Many GPS devices that offer routings for buses and trucks base their directions on general information -- such as routes that are closed to trucks or buses -- rather than actually collecting important data such as bridge heights, GPS experts say.

The Journey Lines incident sheared off much of the coach roof. All those treated at a hospital after the crash were released. Sixteen players stayed home from school the following day, however.

The nearly century-old concrete and brick footbridge suffered only minor damaged.

The driver was cited for "hitting a structure with impaired clearance" and given a $154 ticket.

A spokesman for Garmin Ltd., the manufacturer of the GPS unit used by Journey Lines, said an independent company that also supplies information to online mapping sites provides its underlying data.

"Bus" routes typically steer drivers away from roads or turns where larger vehicles are not allowed but don't take specific bridge heights into account, said Garmin spokesman Ted Gartner.

"The bigger comment here is that drivers always need to obey all the rules of the road at all times," he said. "Stoplights aren't in our databases, either, but you're still expected to stop for stoplights."

A handful of companies offer GPS systems -- mainly used by truckers -- that allow drivers to enter the height of their vehicles and then route them around bridges that would be too low.

"It's such a painful process to collect the data," said Edward Friedman of TeleType GPS, which released its WorldNav truck system earlier this year. "You actually have to ... drive around and look at the heights of the bridges and go to all the counties."

Mark Hornung, senior vice president of operations for the manufacturer of CoPilot Truck, another GPS system that takes clearance heights into account, said some who buy cheaper generic systems wind up in tough spots.

While GPS units have clearly established their value in helping commercial drivers find their destinations and pick routes, the Seattle crash dramatically demonstrates their downside: First, they may encourage drivers to become lazy thinkers and just follow directions and, second, they can be distracting. Some believe they also sacrifice an individuals capacity to remember routes.

Put another way, the driver may take his or her eyes off the road to watch the GPS, thereby reducing concentration on the travel route because he or she is listening (not to something in the background but) to "someone" telling them to do things.

Still, GPS advocates maintain that watching or listening to a GPS device is preferable to reading a map or printed directions while driving. And having a GPS is preferable to aimlessly driving, or not knowing exactly where you are going and how to get there.

It is thought that drivers trying to figure out where they are going become less cognizant of other vehicles around them or drive less carefully.

GPS allows drivers to focus on street or highway conditions instead of desperately searching for a street sign or the street name if using printed or handwritten directions.