The roadway, between Louisiana Street and Haskell Avenue, should only be vacated to make room for the trafficway along a 32nd or maybe 35th Street alignment, commissioners said.
"It doesn't have to be 32nd Street, but it can't be too far south of 31st Street to solve our traffic problem," said Commission Chairman Bob Johnson.
Mike Rees, chief lawyer for the Kansas Department of Transportation, told commissioners the state would restore the abandoned portion of 31st to wetlands as part of the project.
Some Haskell Indian Nations University alumni told commissioners they want the county to vacate 31st Street.
"We would like it to be given back to Haskell," said Thomasine Ross, a member of HINU's Alumni Assn.
She said she hopes KDOT also will include the association in meetings about its plans. Those meetings of interested parties could start next month, Rees said.
Commissioners also heard from critics of KDOT's efforts.
Anna Wilson, spokesperson for the Wetlands Preservation Organization, said the group, which includes several Haskell students and faculty, disagreed with the Bureau of Indian Affairs' involvement in the SLT project.
In late March, the BIA, which oversees HINU, agreed to drop the university's long-standing opposition to the SLT, if 31st Street were vacated and the selected alignment was far enough south of 31st Street to "negate any impacts" on Haskell property.
Wilson said the WPO and others remain skeptical of any trafficway route going through the wetlands because of the historic importance of the Baker Wetlands to Haskell.
Commissioner Charles Jones said Haskell must be involved and support the county vacating 31 Street, before he would vote for it.
"There are too many legal implications, and there will be lawsuits and political fights, if Haskell isn't on board," he said. "I have always been very respectful of Haskell's position."
Jones also questioned what might happen with traffic on nearby streets, if 31st were vacated and the trafficway built to the south.
In October 1999, he said, KDOT released a study showing 10,000 vehicles a day traveled 31st Street between Louisiana Street and Haskell Avenue.
"If you close 31st, you actually would increase the traffic we have on 23rd Street," Jones predicted.
Rees said KDOT plans to have new traffic projections later this year, but city and county officials may have their own numbers sooner.
In January, the city and county hired TranSystems, Kansas City, Mo., to conduct a feasibility study of 31st Street. City and county officials last year discussed improvements from Iowa Street to Haskell Avenue, ultimately extending the road east to O'Connell Road and then to Noria Road. Phase I of the study is expected late this year.
Johnson said the city and county might be able to save some money if 31st Street is vacated.
"To me, it seems to be a great opportunity for us not to improve that road," he said.
Commissioners said they plan to further discuss the trafficway project in August.
-- Staff writer Joy Ludwig can be reached at 832-7144.