SIOUX FALLS, S.D. (KELO) — When Cliff Avenue closes from 56th Street to Tomar Road, 18,000 vehicles a day will need to take a different route to work or play, said Heath Hoftiezer, a traffic engineer with the city of Sioux Falls.

The closing will happen after school closes for the summer, which means northbound traffic that uses Cliff Avenue on their way to Lincoln High School won’t be diverted. But officials have said that section of Cliff Avenue will be open before school starts in August.

Public works engineer John Osman said the traffic will be detoured to Minnesota Avenue when the section of Cliff is closed.

The construction project will create a second lane for traffic so southbound and northbound traffic will have two lanes. There will also be appropriate turning lanes.

A portion of the northbound lanes of Cliff Avenue has been removed near 56th Street. Several trees on the east in the boulevard have also been removed. Trees will also be removed from the west side of Cliff Avenue.

Traffic is down to one lane in each direction.

“As I’ve driven through it, I thought traffic flow looked good,” Osman said.

Although one lane in each direction is open, the construction is causing some drivers to choose alternate routes.

So far, the Cliff Avenue construction is impacting most northbound traffic during the morning peak, Hoftiezer said.

“So far, intersection counts at 26th and Southeastern are showing an increase of 220 vehicles between 7-9 a.m. and an increase of 190 vehicles at I-229 and Minnesota between 7-9 a.m.,” Hoftiezer said.

Outside of those peak times, there are no noticeable changes in counts, he said.

When an arterial route such as Cliff Avenue is reduced to a single lane, the city typically sees that about 20% of the traffic finds new routes, Hoftiezer said.

The northbound side of Cliff Avenue near 56th Street is being removed so another lane can be added.

But when that section of Cliff Avenue closes on May 31 to all through traffic, the detour starts.

Hoftiezer said the city will monitor the increased traffic on the detour to Minnesota Avenue as well as other routes drivers may take.

“We will have to track where (drivers) are and make adjustments accordingly,” Hoftiezer said.

Should detoured traffic on Minnesota Avenue cause issues with backed-up traffic in turning lanes or similar, for example, Hoftiezer said the city would need to make possible adjustments in those areas.