The Georgia Department of Transportation Wednesday morning began making changes to the I-75 HOV exit ramp that was the site of this month's deadly charter bus wreck.

The ramp was closed to traffic just after 9 a.m., and the DOT said it would remain closed until 3 p.m.

Because of the bus crash, which one official termed "utterly preventable," the DOT will make changes at all seven of metro Atlanta's left-hand HOV interchanges.

The changes proposed for the I-75 Northside Drive exit where the crash occurred are at the ramp itself; no immediate changes are being made to the signs approaching the exit to help keep drivers from taking the ramp in the first place. National Transportation Safety Board officials said the bus driver apparently took the exit ramp thinking it was the highway carpool lane.

State Transportation Commissioner Harold Linnenkohl said the changes to the Northside Drive exit, which should be complete in three weeks, do not mean the state is admitting it had done anything wrong, but rather that it is enhancing clarity.

The immediate changes include markings on the pavement like the word "EXIT" near the HOV diamond, bigger stop-ahead signs and stop signs at the top of the ramp, widening the dotted line that cuts off the exit from the HOV lane and making it yellow, and raised reflectors laid down in a line to bring attention to the new pavement markings and give drivers the feel of a rumble strip.

The bus that crashed March 2 was carrying the Bluffton University baseball team from Ohio to Florida. After the bus with 35 people aboard climbed the exit ramp about 5:30 a.m., it crashed into the Northside Drive barrier wall, and flipped over the wall back onto the interstate below. The accident killed seven people. Two remain hospitalized in Atlanta, including the coach.

For Gene Darbyshire, who was a co-worker in Ohio with the bus driver, Jerome Niemeyer, the changes don't go far enough.

He said the exit, which he drove after the crash, is "about the poorest thing I've ever seen in all my years of driving." He wants the words "exit only" and better warnings ahead.

As passionately as he feels about the changes, though,

he said, "It's too late, you know?"

DOT officials said the changes focus on drivers unaccustomed to the left-hand exit, as Niemeyer apparently was. The seven left-hand exits are all on I-75, I-85 or the Downtown Connector.

"Obviously, this is in response to the accident involving the bus," said DOT spokesman David Spear. "Those people lost their lives for reasons that were utterly preventable. Tragically, we can't do anything about that. But this is designed to hopefully help prevent anything like that from ever occurring again."

Asked who could have prevented the crash, Linnenkohl said he did not want to "point fingers at anyone" but the ramp and its signs met federal standards, and the driver apparently mistook the exit ramp for a travel lane.

Department officials said they were also considering bigger changes that would take time for engineering, such as overhead signs or flashing lights.

DOT spokeswoman Carrie Hamblin said it would take time to study potential overhead signs' weight and the winds at the site.

"We don't want to rush in. We can't say, 'We know what it's like, we have signs up in that area,' " she said.

The changes so far do not affect the signs that alert HOV drivers a mile ahead and a half-mile ahead that the Northside Drive exit is coming up. Those signs do not note that the exit will be on the left.

Experts say that drivers expect exits to be on the right, so signs for left exits need to be especially clear.

A lawyer who has sued DOT before said that taking action now probably would not hurt DOT in court, should the crash victims decide to sue.

"Generally under the law, subsequent remedial measures are not admissible at trial," said the lawyer, Clark McGehee.

DOT has provided documentation over a nine-year period of dozens of crashes in the area of the Northside Drive and I-75 interchange, including a small number involving the HOV exit ramp. Among those crash reports released, the only fatal ones involve that ramp.

Sign experts interviewed by The Atlanta Journal-Constitution have criticized the signs in place at and approaching the ramp, or suggested changes.

Fred Hanscom, a sign expert, called one of the exit signs "potentially a killer." He declined to comment on the exits this week because he had been contacted by potential litigants and expected to be retained as an expert witness.

Staff writer Mike Morris contributed to this report.