If the Utah Transit Authority wants to put light rail on a six-block section of 400 South, the tracks will have to be in the parking lanes on either side of the street - not in the center.

That's the only configuration Utah Department of Transportation executive director Tom Warne says he would allow on the state-owned thoroughfare in downtown Salt Lake City.UTA and city officials, however, hope they can change Warne's mind as negotiations on the alignment of a proposed west-east extension for the agency's light-rail mass transit system continue.

"They're still trying to get it in the middle of the road," Warne said Wednesday after a midday meeting with UTA of-ficials. "So far, we've been unable to come up with a satisfactory solution with double tracks in the middle of the street.

"We believe we could live with the tracks being on either side of the street on the curb lane, where the tracks run on the curbs and essentially the sidewalk becomes the (passenger-station) platform."

To Warne, that is a significant compromise on UDOT's part. The department would rather not have light rail on 400 South at all. When the I-15 reconstruction project is finished in three years, the road will serve as a freeway access for high-occupancy vehicles traveling to and from the south, and for all traffic moving to and from the north.

Warne wants to ensure 400 South traffic will flow smoothly for years to come. He'd like to have the ability to make future enhancements, such as double left-hand turns and free-flowing right-turn lanes. Light rail would negate such improvements, he said.

UTA originally proposed reducing the width of lanes on 400 South to 10 feet but has since agreed to 12-foot lanes with a narrow sidewalk and tracks wiggling down the center of the street to accommodate left-hand turns. Warne feels those turn lanes wouldn't be large enough.

"Our biggest concern is through traffic, and then another significant concern is the left-turn movements that are very, very important on 400 South," Warne said.

The side-street alignment on 400 South would be necessary only between 400 West and 200 East. The tracks could converge in the middle of the street beyond 200 East as they head for the University of Utah.

John Inglish, UTA's general manager, worries that side-running light rail would conflict with some 45 accesses into businesses between intersections on that six-block stretch of 400 South. In his mind, the technical merits of putting light rail on the curb instead of in the median are not yet conclusive.

"We did say to him that if that's what it had to be, then we'd make it (curbside alignment) work," Inglish said Thursday. "It's important that it be on 400 South. I just hope we don't make a mistake and both of us regret it later, so that's why we're continuing to study it.

"We've met most, if not all, of the conditions that we think were of concern to him. . . . I'm not sure why he's so firm on that position, if in fact he is."

The west-east line, a 10.9-mile extension that would connect Salt Lake International Airport with downtown and the university, remains under study.

UTA and city officials, bolstered by recent congressional action that could lead to 100 percent federal funding for the estimated $374 mil-lion project, hope to have the west-east line in operation before the 2002 Winter Games. The main north-south line, now under construction, is set for completion in March of 2000.

Warne did say talks would continue: Details of how light rail would function on 400 South still need to be worked out.

"We don't need anything formal at this point other than knowing that 400 South works," Salt Lake Mayor Deedee Corradini said. "Everyone's in agreement that 400 South works."

If, that is, light rail stays on the side, Warne reiterated. He plans to present his preliminary decision to the state Transportation Commission at its July 22 meeting for an "advisory opinion." But the ultimate fate of light rail on 400 South is up to him.