Around 10 a.m. today, the MBTA resumed regular speeds for Red Line trains in Cambridge after crews repaired a crack found in a rail between the Central Square and Harvard Square stations. ending a slowdown that started around 9 a.m. today.

T spokesman Joseph Pesaturo said in e-mails that the track was repaired around 10 a.m. The initial problem was discovered around 9 a.m. on the northbound track. As a safety precaution, trains made their way through the impacted area at reduced speeds.