E, F, M and R train riders: Expect crowded trains and rush hour delays from now through Labor Day. 

The MTA is urging riders to leave earlier and plan ahead while the agency repairs express tracks from Monday, Aug. 17 through Friday, Sept. 4. 

Some express E and F trains will run on the local track, and all trains will travel 10 mph through construction zones, reducing the number of trains in service, the MTA said in a press release. 

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The express trains traveling on the local tracks means less M and R trains will be able to run on the same tracks. 

E trains will not run to or from Jamaica- 179 St., and riders should instead take the F train and transfer at Union Turnpike. 

The MTA said the repairs are “necessary to keep the express tracks in a state of good repair along the Queens Boulevard line, which is the second-busiest line in the entire subway system,” and that the work was scheduled for the last three weeks of the summer, which sees one of the lowest number of riders.

Subway riders can check train statuses online at http://www.mta.info

More bad news for transportation in Queens came on Monday, when NYC Department of Transportation said motorists on the Brooklyn Queens Expressway should expect delays in both directions under the Woodside Avenue and 69th Street bridges starting August 21. 

The single and double lane closures are for steel cleaning and repainting are expected to last through Oct. 31. More information on the project is at facebook.com/bridgepainting

RELATED: More riders, more problems: MTA says high ridership leads to operational challenges