Examining the 3 alternatives being considered for the overloaded 70/63 connector

New flyover ramps or a diverging diamond interchange are among the possibilities being considered to improve the Interstate 70 and U.S. Highway 63 connector.

The Missouri Department of Transportation presented the options Thursday as part of an initiative to make improvements along an 18-mile stretch of I-70 from the Missouri River to the Centralia Route Z exit.

Funding has already been identified for this section of the Improve I-70 project through the State Transportation Improvement Plan, which could see I-70 eventually widened to six lanes through Columbia.

Previously: Have a solution for the 70/63 interchange? MoDOT earmarks $140 million, seeks public input

MoDOT personnel teamed with engineers and environmental planners from Crawford, Murphy and Tilly (CMT) and HG Consult Inc. to develop possible solutions.

Three connector options

The first alternative includes tri-level flyover ramps from northbound 63 onto westbound 70 and from eastbound 70 onto southbound 63, completely avoiding the current connector.

These traffic flow directions experience a majority of the traffic.

The flyover seems to be the most popular option so far based on the first week of an online public comment portal, said Brandi Baldwin, Improve I-70 project director.

Baldwin also is the director for the Missouri River Bridge at Rocheport replacement project.

"There is a lot of good support with the alternatives," she said. "The two movements we are proposing (with the flyover) reduces about 17% of the traffic in the connector area."

MoDOT estimates the flyovers would have average daily traffic of 5,500 to 6,500 vehicles depending on direction.

MoDOT also counted turning movements regardless of the number of vehicles traveling through the connector on a daily basis. This was upward of 190,000 movements through the connecter, Baldwin said.

"This is all the movements combined, so that's a lot of traffic," she said.

The flyover plan includes a single-point urban interchange at the connector, meaning only left turns would have signal lights, while all right turns would be yielded turns.

A similar interchange is in Hannibal.

"The advantage there is you take all those traffic movements and put them into one signal. The left-turn movements don't cross each other," said Brian Eads, project manager and traffic engineer with CMT.

The second alternative includes a looped ramp from northbound 63 to westbound 70 instead of the flyover, with a flyover from eastbound 70 onto southbound 63. This option would have business access impacts at Clark Lane to Steak 'n Shake, Bob Evans and the Best Western Plus hotel. This version also could have a diverging diamond interchange, similar to what is at the Stadium Boulevard exit on 70.

The third alternative keeps much the same layout of the connector as it is now, but with additional traffic lanes and some shifting of intersections to connect to Conley Road and the section of Business Loop 70 that is home to TGI Fridays, hotels and Moser's grocery store.

The first two alternatives remove the left-hand exit on 70 to the business loop, while the third does not.

Community input

The consensus among several attendees of a public meeting Thursday at the Activity and Recreation Center was that something has to be done about the connector.

Among the three presented options, there was not one that stuck out as a favorite.

The project is in an early phase of a design-build process, which has a shorter award timeline because the design contractors also do the construction, rather than putting the project out for bid to find a construction contractor following design completion.

When the connector first was built, MoDOT should have considered a cloverleaf, said Columbia resident Bill Paten, who lives off of Mexico Gravel Road north of the connector.

"They wouldn't have had all these buildings around. Now they have to go up in the air to get over and under. It will work. It will just cost a ton of money," he said, adding he did not yet know enough to choose a preferred option.

Resident David Delong is concerned about population growth in regard to the proposed options at 70 and 63, while noting something still needs to be done at the connector.

"How far down the road are they looking for population growth in the area and traffic?" Delong said, adding he hopes the updates are not just a Band-Aid. "Are we not looking far enough ahead?"

Baldwin addressed these concerns. Part of the planning process included using traffic volume growth projections through 2045.

"We used past data for growth and try to match that trend," she said.

Since so much traffic on 70 is from Columbia and Boone County residents, Jan Lang had hoped additional exits on 70 would be proposed for other connections into other frequented areas by motorists, she said.

While she liked the idea of the flyover ramps, she also was concerned that would mean people could avoid local businesses.

"Some of the (plans) take the exits further up, which may not be the best for the business, but it is away from that intersection," she said. "... Anything they can do to get traffic off of the (70/63) interchange is ideal. (MoDOT) has to somehow think of another interchange further west."

Resident Christopher Brown said the interchange is the bane of his existence. He lives off of Clark Lane east of the interchange.

"I'm glad something is going to be done, even it is in 2025," he said, adding he has been involved with three minor crashes at the connector. "Something has to change because Columbia keeps growing and (the connector) is impacting the northeast portion of town."

Charles Dunlap covers local government, community stories and other general subjects for the Tribune. You can reach him at cdunlap@columbiatribune.com or @CD_CDT on Twitter. Please consider subscribing to support vital local journalism.

This article originally appeared on Columbia Daily Tribune: MoDOT proposals could reduce traffic at 70/63 connector by nearly 20%