Caution: Gulf Freeway traffic nightmare ahead as TxDOT demolishes FM 646 overpass this weekend

The first phase will include the demolition of the FM 646 overpass, construction of the I-45 northbound mainlane overpass, and reconstruction of the intersection and frontage roads. The first phase will include the demolition of the FM 646 overpass, construction of the I-45 northbound mainlane overpass, and reconstruction of the intersection and frontage roads. Photo: Courtesy TxDOT Photo: Courtesy TxDOT Image 1 of / 9 Caption Close Caution: Gulf Freeway traffic nightmare ahead as TxDOT demolishes FM 646 overpass this weekend 1 / 9 Back to Gallery

A total closure of the FM 646 overpass at the Gulf Freeway will likely cause headaches for drivers, but the end-game will be all worth it.

Starting Friday night at 9 p.m., Texas Department of Transportation crews will close the bridge indefinitely as they make way for a new intersection.

TxDOT plans to demolish the bridge and pave new lanes for FM 646 to go underneath the Gulf Freeway. The Gulf Freeway main lanes will eventually go over FM 646.

Two northbound main lanes from FM 517 to FM 646 will be closed beginning on Friday, March 1, at 9 p.m. until midnight on Saturday, March 2, according to TxDOT.

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During the closure of FM 646 at I-45, traffic will be detoured to the frontage road. Those traveling westbound on FM 646 will travel onto the I-45 northbound frontage road to SH 96, U-turn and travel on the southbound frontage road to FM 646.

Those traveling eastbound on FM 646 will travel onto the I-45 southbound frontage road to FM 517, U-turn and travel on the northbound frontage road to FM 646.

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The intersection is a main hub for business in the League City area. And the Gulf Freeway is the main artery for traffic between Galveston and Houston.

This portion of the I-45 expansion project is anticipated to take approximately six months to complete.

Jay R. Jordan covers breaking news in the Houston area. Read him on our breaking news site, Chron.com, and our subscriber site, HoustonChronicle.com | Follow him on Twitter at @JayRJordan | Email him at jay.jordan@chron.com | Text CHRON to 77453 to receive breaking news alerts by text message