Two men were injured, one seriously, when a van ploughed through a wall and landed on tram tracks 10ft (3m) below.
They were taken to hospital following the crash in Sale, Greater Manchester, in the early hours of Monday, police said.
Morning rush-hour Metrolink services between Altrincham and Old Trafford were suspended in both directions.
The van was removed at 07:30 GMT, but commuters were told to use replacement bus services pending an inspection.
By about 09:00 tram services had resumed, although Metrolink warned "severe delays" were expected to continue until later in the day.
The crash happened at 02:20 near the junction of Marsland Road and Hope Road, opposite Brooklands station.
Metrolink staff were at the station to point commuters - many of whom did not know what had happened - towards the buses.
Services on the Altrincham line only operated between Old Trafford and Piccadilly while the tracks and overhead lines were being inspected.
A tram arrived at Brooklands station from the direction of Manchester at 08:32 - it was carrying no passengers and had the sign "tram on test" on the front.
It was running on the stretch of track where the van had crashed.
Extra trams were running to Sale Water Park - about two miles away from Brooklands - for passengers to use the park-and-ride site and Manchester Airport line as an alternative.
At the scene
By Ian Shoesmith, BBC News online
The Metrolink is always very busy from around 7:30 until 9:00 every weekday.
Ensuring enough bus capacity to get commuters to work this morning would clearly prove very difficult.
Not the best of Monday mornings... especially if you happen to be from the red half of Manchester - Old Trafford is only four short stops down the tram line towards Manchester City centre.
Passengers were able to use their tram tickets on the 263, 256 and 11 bus services, Transport for Greater Manchester (TfGM) said.
Northern Rail services were also accepting Metrolink tickets from Navigation Road.
Danny Vaughan, head of Metrolink at TfGM, said: "I'd like to apologise for any inconvenience this incident may cause, we will ensure it is dealt with as quickly as possible and keep our customers updated."