An interchange connecting I-84 with southbound I-15 is a good idea but not likely to materialize, says a Utah Department of Transportation official.

"We see a need, but I don't know how it ranks in terms of priority or traffic usage," said Lynn Zollinger, District 1 preconstruction engineer for UDOT.Residents working with a contractor doing a corridor study on U.S. 89 have said they believe the key to resolving traffic-safety problems is getting interstate traffic, especially semitrailer-trucks, off the highway by providing an exchange from I-84 onto southbound I-15.

The two interstates meet up in the Riverdale-Roy area, but traffic has to exit I-84 and travel along Riverdale Road to get onto southbound I-15.

Zollinger said UDOT doesn't deny the interstates should hook up.

"The basic theory of it is fine. When two interstates intersect, there ought to be full capability of going in any direction you desire without having to leave the interstate," he said.

"But when the original design was drafted about 20 years ago, a decision was made to use Riverdale Road as the connecting link, which was not necessarily a good decision," Zollinger said.

Although the need for an exchange now is apparent, the engineer said connecting I-84 with southbound I-15 presents some serious difficulties.

Zollinger said I-84 comes up at a sharp angle from the south where it intersects I-15. That, combined with the amount of land needed for the right of way, makes the proposition especially difficult and expensive, Zollinger said.

One problem with determining priority is that there are no figures on the amount of traffic leaving I-84 at the mouth of Weber Canyon and going southbound on U.S. 89 that might use such an exchange, he said.