The “big squeeze” that will have motorists sharing one side of the Lowry Hill tunnel this summer will be delayed a month by a 4-by-4-inch problem.

The tunnel’s vintage yellow tiles proved very difficult to match.

Tunnel tile might seem like a fairly simple element in a $46 million project that includes fixing 50 bridges along Interstate 94 between Nicollet Avenue and Brooklyn Center.

But that style and color of tile isn’t widely made anymore, so finding replacements turned out to be a challenge, said Minnesota Department of Transportation spokesman David Aeikens.

As a result, St. Michael-based contractor PCI Roads informed MnDOT this week that work inside the tunnel will begin June 26 instead of mid-May.

The original yellow tile was installed when the tunnel was built in 1969. It is needed to protect the concrete walls from damage.

“MnDOT is only replacing the damaged tiles, so the new pieces have to match,” Aeikens said. “We are working to preserve the original look of the tunnel.”

MnDOT’s contract with PCI Roads allows the company to reschedule aspects of the work “at their discretion,” Aeikens said.

“From my understanding everything has been worked out,” he said.

The traffic switch will be in place for 70 days. Drivers will find some lane closures starting June 22 as MnDOT prepares for the project.