CHICAGO (WBBM) — Riding the Loop ‘L’ this weekend could leave you a bit disoriented.

Work to install new switches and signals at a key CTA junction point will cause delays beginning at 4 a.m. Saturday and lasting until about 8 p.m. Sunday.

The work is taking place at Van Buren and Wabash, a spot where the Orange, Green, Brown and Pink Lines meet.

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Orange, Brown and southbound Green Line trains will be rerouted this weekend.

Southbound Brown Line trains entering the Loop will run clockwise, with Clark/Lake as the first stop and Washington/Wells as the last stop.

Orange Line trains entering the Loop will operate counterclockwise with Adams/Wabash as the first stop and the Harold Washington Library as the last stop.

Southbound Green Line trains will be rerouted along Wells and Van Buren, instead of their normal route along Lake and Wabash. CTA officials said that northbound Green Line trains will make regular stops.

Pink Line service is unchanged.

CTA officials said that when switches are thrown they will be thrown by hand, with personnel at ground level, adding to the delay.

The upgrades to the signaling system are the first on the Loop in nearly 30 years. CTA expects the upgrade to allow signals to change more quickly, reducing delay times, especially during rush hours. As a result, trains will be able to run a bit more closely together even when switches are thrown.

Service should return to normal Sunday night. The long-delayed signal upgrading project in the Loop is expected to wrap up before the end of the year.