NEW YORK - Mayor de Blasio is allowing for certain motorized bikes to be used on city streets.

The Department of Transportation announced Tuesday that pedal-assist bicycles will be made legal.

The bikes are motorized, but also require pedaling.

Mayor de Blasio says the rule will lower congestion and give commuters more travel options during the L Train shutdown next year.

"One thing we've seen in other cities that have had pedal-assisted bikes, it encourages a lot more people to cycle and it enables them to cycle for trips often two or three times longer than they would for example on a city bike. And it encourages people in times when they may have chosen to drive to ride a bike instead," said DOT Commissioner Polly Trottenberg. 

The DOT has also made operating throttle electric bikes illegal.

They do not need to be pedaled and can travel over 20 mph.

The NYPD says by the end of 2017, it had seized just over one thousand e-bikes and issued nearly 900 moving violations.