A new report says the MTA and Department of Transportation are not doing enough to make the city's bus system run smoothly.

The Riders Alliance, Straphangers Campaign and other groups united with 37 elected officials last year to develop the Bus Turnaround Campaign to spotlight the ongoing decline of bus service quality and offer policies for improvement.

Both agencies were given six categories to improve procedure. The DOT earned a "D+" in designing streets that prioritize buses. It received an incomplete in redesigning the bus network and routes for more frequent and efficient service and a "C" in making using the bus easy and intuitive.

For the MTA, it received a "B-" in redesigning the bus network and routes; an incomplete in transforming how New Yorkers get on the bus; an "F" in adopting better methods of keeping buses on schedule; and another incomplete in increasing transparency about bus performance.

Advocates say that at a time when ongoing subway delays should push more riders to use buses, city bus usage actually fell by more than 2 percent in the first six months of 2017. That's in addition to annual ridership decline.

The MTA and DOT responded by pointing to faster travel times on select bus routes with Transit Signal Priority technology, which allows buses to trigger longer green light signals. The DOT says it's quadrupling its installation rate, covering more than 1,000 intersections in total and 15 additional routes by 2020.

"New York City's bus lane network has seen unprecedented growth in recent years. We have added an average of 8-9 miles of new bus lanes annually from 2012 to 2016," says a DOT spokesperson.

The MTA also says it has added more real-time tracking of buses to decrease bunching, adding, "The MTA is committed to improving bus service citywide and has implemented a toolbox of best practices to speed rides and improve the customer experience."

Bus riders say they will see if the promised changes make their commutes shorter and smoother in the near future.