Everybody from motorists to bus riders to downtown skyline gazers soon will start noticing signs of what is expected to be one of downtown’s larger developments in recent years.

Lawrence city commissioners on Tuesday are scheduled to approve the final site details for the five-story Marriott hotel and retail development at the southeast corner of Ninth and New Hampshire streets. The approval is expected to clear the way for construction to begin next week and last for the next 15 months.

“It is going to be a great project,” said Micah Kimball, project architect for the development. “We’re trying to minimize any impacts on traffic or the surrounding area. It is a tight site, but we’re used to that.”

Riders of the city’s public transit system may be the first to feel the impact of the more than $10 million project. The city will close its transit hub at Ninth and New Hampshire on July 17. It will move to the 700 block of Vermont Street, across from the construction site of the Lawrence Public Library.

City officials are posting signs at the intersection and on the transit buses to notify riders of the impending change.

“The biggest thing for us right now is to get the message out to the public,” said Robert Nugent, the city’s public transit administrator. “We thought we would have 15 to 30 days to make the change, and we have about a week. We don’t want people standing around down there for a bus that isn’t going to come.”

Nugent said the new transit hub, which is where riders often transfer to different buses, will require several route changes. He said riders of Routes 1, 3, 4, 6 ,7, 10 and 11 should look for notices about changes in bus stops in the downtown area.

Motorists also will have to make adjustments at the intersection. Kimball said through traffic will be allowed through the intersection during construction, but it will be shifted to different lanes.

During much of the construction period, the portion of the northbound lane of New Hampshire Street in front of the project will be closed. The northbound traffic will be shifted to the center turn lane of New Hampshire Street. Also, the portion of the eastbound lane of Ninth Street that runs along the side of the site will be closed. The eastbound traffic will be shifted to the center turn lane on Ninth Street.

Motorists, though, won’t find a roundabout at the intersection anytime soon. The development group, which is led by Lawrence businessman Doug Compton and Lawrence architect Mike Treanor, originally had proposed a roundabout for the busy intersection. But that idea met opposition from some commissioners, and it was not included in the final set of plans.

In addition to traffic details, commissioners also will be asked to approve the final design elements of the site and building. Many of those details remain unchanged from last year when commissioners approved an incentives package for the project. Those details include:

• A building height of five stories at its tallest point. The tallest point is at the northwest corner of the site, where the building will stretch to 64 feet. The building’s eastern edge, which is the edge closest to an adjacent neighborhood, steps down to about 40 feet.

• The hotel, a Marriott TownePlace extended stay hotel, will have 91 rooms. The hotel will have a ground floor lobby and indoor pool, with rooms on floors two through four.

• The building’s top story will include three luxury apartments for rent.

• The ground floor will have space for about 7,000 square feet of retail space. Lawrence attorney Bill Fleming said a tenant hasn’t yet been found for the space, but efforts will intensify now that the project is set to begin construction. He said a user that could provide a food and convenience market remains the company’s top choice for a tenant.

• The project will include a 22-foot wide patio area between the hotel building and the adjacent Lawrence Arts Center to the south.

• The angled parking spaces along the east side of New Hampshire Street will be removed and replaced with a combination of parallel parking spaces and a drop-off lane for hotel guests. The changes will result in fewer on-street parking spaces in the block, although the current spaces are largely occupied by the transit hub. The project will include a 102-space below-ground parking garage to serve the hotel and retail development.

City commissioners will meet at 6:35 p.m. Tuesday at City Hall.