The M train returned to service Monday after authorities shut down the line to make time for upgrades last year.

Straphangers are celebrating the news. They say it's been rough having to take shuttle buses or other alternative routes to get around.

The $163 million upgrade project kicked off last July. The MTA says it needed to modernize and stabilize the system, which is more than 100 years old.

Upgrades include new tracks, new signal equipment and improvements to reduce noise pollution.

Officials say the project ended on time and on budget.