The driver of the bus that crashed Sunday outside Frederick, Md., killing five persons and injuring 12 others, received 22 traffic tickets, including 13 for speeding, between 1956 and 1975, state officials said yesterday.

In addition to the speeding tickets, George Whalan Brown, 68, who died from injuries suffered in the accident, was ticketed for nine moving violations, including running three red lights, improper passing and reckless driving, according to Steve Horowitz, spokesman for the Maryland Department of Motor Vehicles.

Brown's driving record shows no violations or tickets since 1975, Horowitz said.

Investigators said that driver error appears to have been the cause of the accident, which occurred at 12:40 p.m. Sunday on a rain-slick I-70 highway bridge. The bus, operated by the Baltimore Motor Coach Co., was carrying 17 persons from Baltimore to the race track at Charles Town, W. Va.

"We still haven't determined exactly how it happened . . . but at this time it appears to be driver error -- he was speeding," said Trooper Timothy Miller, who is handling the accident report for the Maryland State Police.

Another trooper, Frank Woullard, said the bus may have been traveling 65 to 80 miles per hour, according to the accounts of some witnesses. The speed limit in the crash area is 55 miles per hour.

An autopsy on Brown is scheduled today, officials said, and will include tests for his blood alcohol level and for the presence of drugs or other substances.

The bus accident was described as the worst in this area since 1981 when a commuter bus hit a bridge parapet in Triangle, Va., and fell 25 feet into a shallow creek. Eleven people were killed. The accident was blamed on a mechanical problem with the bus, which was traveling from the Pentagon to Fredericksburg, Va.

Five agencies, two federal and three state, now are looking into the Sunday accident, in which all but two passengers were flung out of the bus when it hit a section of the guardrail of the bridge over the Monocacy River and then zigzagged across the two-lane westbound bridge before stopping.

Injuries probably would have been reduced and lives saved if passengers had had seat belts to wear, officials said, but this bus, like nearly all commercial buses, was not equipped with them.

" . . . If you are thrown out of the bus, you're going to be seriously, if not fatally injured," said Claude H. Harris, the investigator in charge for the National Transportation Safety Board. Harris said the bus driver was not wearing his seat belt, in violation of federal regulations.

Harris said it probably also would have helped passengers if the bus, a 1963 General Motors Model 4106, had been "a little stronger" structurally. He said that school buses have been made stronger since 1977 to conform to strict federal standards. Passengers in a school bus probably would not have been ejected in a crash as severe as the one Sunday and as a result would have suffered only minor injuries, he said.

The ejection of most passengers apparently occurred when the pushout emergency release windows opened and people were flung out through the open windows. The driver and one passenger were thrown out the front of the bus and down an embankment to the edge of the Monocacy River more than 80 feet below. Both men died.

The bus itself appeared to have been operating in satisfactory condition, so far as investigators could determine yesterday.

Harris said the brakes were functioning properly, the suspension system was intact and the tires had good tread. The two front tires appeared to be new, he said.

The bus was inspected June 26 by the Maryland Public Service Commission, which has jurisdiction over intrastate carriers such as the Baltimore Motor Coach Co. Thomas Lovelace, director of the PSC transportation division, said the bus that crashed Sunday was one of 10 the company was operating at the time.

Officials of Baltimore Motor Coach Co. declined yesterday to answer any questions about its operation or its employes.

Lovelace and others familiar with the company said it has been in business for 40-50 years. They said its run from Baltimore to the West Virginia race track is a scheduled trip that the company operates in addition to a chartered bus service.

The 1963-model bus that crashed was one of the oldest buses in the company's fleet, Lovelace said. He described this particular model as "one of the workhorses of the industry -- like the 727 of the airlines."

But Robert Forman, vice president of safety and security for Trailways Line Inc., said that the 1963 bus "is in the last days of its life cycle." He said that the oldest bus in his company's fleet is a 1973 model.

Forman said the average age for bus drivers is the mid-40s, but that they can work up to age 70 under federal laws. A bus company is responsible for making sure its drivers have a bi-annual physical checkup, in keeping with federal rules, he said.

The federal Bureau of Motor Carrier Safety checks bus company records for compliance with such rules. Bureau director Kenneth Pierson said yesterday that the Baltimore Motor Coach Co. was rated satisfactory when last examined in 1982. He said the bus companies are checked about once every five years.

During the examination, the bureau looks at the company's screening and hiring of drivers, driver qualification files, and vehicle maintenance records.

Several of the injured in Sunday's crash were race track regulars, who had known each other casually as passengers on the Sunday bus to Charles Town over the past few years.

One was Wester Clark, 57, a tractor-trailer driver for Consolidated Freightways of Baltimore, who said he has been going to Charles Town for 25 years.

He spoke in a telephone interview from his bed at Frederick Memorial Hospital, where he is listed in satisfactory condition with a fractured shoulder, a cut on his right arm and numerous scratches on his back.

With rain falling, he said, he got on the bus with a half dozen other passengers as the bus stopped in front of the Double T Diner in suburban Catonsville before heading out onto I-70 toward Frederick.

Clark, a widower, said the driver was not the regular Sunday driver.

"It was a new guy I didn't know," he said. He said he also noticed that the bus was less than half full. It carried only 16 passengers, which Clark attributed to the opening last weekend of the race track in Timonium just north of Baltimore. It is much closer for Baltimore racing fans than Charles Town, which is 70 miles away.

"Usually the bus is packed," Clark said. "If it had been full and I couldn't get on, I might have gone to Timonium instead."

He said he climbed aboard and sat in an aisle seat four rows behind the driver and began chatting with a seatmate. "We were looking at the racing form, and then I fell asleep," Clark said.

"The next thing, I woke up when the bus started slipping and sliding," he said. " . . .I heard people screaming. I was thrown out the front of the bus. I went sliding down the bridge surface 30 or 40 feet."

He said he managed to get up, "and I went back to the bus and tried to help the other people."

Asked if he planned to return to Charles Town, Clark said, "Yeah, I'll go back up there. . . .I'm not scared to ride the bus. I drive a truck myself."

Dead in the crash were four Baltimore area residents: Harry Bernstein, 75; Duxie Lee Sr., 56; Floyd M. Brown, 64, and Irvin A. Myers Sr., 81, as well as driver George Brown.

George Brown had lived since 1977 in a two-bedroom apartment in a housing project at 903 Pennsylvania Ave. near downtown Baltimore, according to the apartment manager. Neighbors said Brown, who was married, had four grown children.