NEWARK - (AP) - Amtrak will begin track work on theNortheast Corridor Friday that is expected to cause delays forpassengers on four NJ Transit rail lines.

Amtrak will replace concrete railroad ties on Track 1 into NewYork between Metropark and Rahway. The ties are being replaced toavoid speed restrictions.

Amtrak and NJ Transit trains will have three tracks availableinstead of four until the work is finished on Aug. 30.

Riders on NJ Transit's North Jersey Coast, Northeast Corridor,Midtown Direct and Raritan Valley lines may experience delays of upto 10 minutes.

The expected delays come after 12 incidents in July led to majorservice disruptions for NJ Transit train passengers. On timeperformance for NJ Transit trains in July was at its worst levelsince December 2007.