[Update: This week’s rains forced a delay in the lane shift, which is now scheduled to be in place by Saturday morning.]

Drivers traveling into or through Baltimore on Interstate 95 are going to encounter a construction project that will replace the highway’s concrete deck along the 4.4 miles between the Fort McHenry Tunnel and Exit 50 at Caton Avenue.

Nothing like this has happened since the tunnel opened in 1985. If your summer vacation drives take you through Baltimore, if you plan to see the Orioles or Ravens, or will be visiting the Inner Harbor, Fells Point or Fort McHenry, you will want to be aware of this work, which is scheduled to end in 2016.

The Maryland Transportation Authority project will shift lanes, reduce lane widths, eliminate shoulders, temporarily close ramps and require some detours.

A phase of this work, scheduled to begin by Friday Saturday morning, weather permitting, will split the traffic pattern on southbound I-95 between Route 295 (Russell Street) and I-395. One lane will go to the left and two lanes will go to the right around the work zone.

This pattern is scheduled to remain through June 15. Beginning on that day, the ramp from southbound I-395 to southbound I-95 will be reduced to a single lane for about two months. The transportation authority says additional changes in traffic patterns will occur on both sides of I-95 through the summer.

The speed limit on northbound I-95 between Caton Avenue and the tunnel and on southbound I-95 between I-395 and Route 295 was cut from 55 mph to 50 mph for the project.