Merchants and others opposed to the county's plans have asked the county to build a temporary bridge during the repairs.
Kroboth said Tuesday that the county commissioners still can approve a temporary bridge, but now would have to issue a change order to do so.
He said while there is federal money available for a temporary bridge, adding one would push the project into next year because of added time to acquire permits and rights of way.
Kroboth and other county officials have said the sides and bottom of the historic bridge, which was built in 1833, are in immediate need of repairs that cannot wait until next spring.
Commissioners President John F. Barr did not vote Tuesday because he was absent from the meeting.
Barr has been the only commissioner to argue for a temporary bridge, saying the county needs to do more to protect businesses.
The commissioners, who are on vacation next week and do not meet again until June 3, said Tuesday that they could not wait two weeks to get the project moving.
"The longer we wait, we could miss the construction season entirely and be into next spring," Commissioner William J. Wivell said.
Barr could not be reached for comment Tuesday.
The county has held two public meetings in the last three months about the project.
At both meetings, several business owners said their shops will be hurt and in some cases could go under because of the closure of the bridge, which carries 9,000 cars per day across Antietam Creek west of Funkstown.
Wivell said Tuesday that some business owners have asked for temporary signs alerting drivers who are detoured by the closure that businesses are open. He said such signs are "a good idea."
Commissioner James F. Kercheval asked for incentives to be added to the contract that would pay the contractor $1,500 for every day it finishes early.
However, merchants have said any prolonged closure will take a toll on their businesses.
Steve Demory, owner of Demory's Christmas Memories on East Oak Ridge Drive, said businesses suffered last year when the bridge was closed for several weeks.
He said many shops will not survive a five-month closure this year, especially with the economy in a lull.
"I'm going to have to put my business up for sale," Demory said. "I don't see any alternative at this point."
How they voted
The Washington County Commissioners voted 4-0 Tuesday to advertise bids for a project to repair a stone-arch bridge on East Oak Ridge Drive in Funkstown.
Commissioners Vice President Terry L. Baker - Yes
Commissioner Kristin B. Aleshire - Yes
Commissioner James F. Kercheval - Yes
Commissioner William J. Wivell - Yes
Commissioners President John F. Barr was absent.