Philadelphia’s new street sweeping program has hit a road bump: The trucks are too wide to fit down some of the city’s narrow, colonial-era streets.

Philadelphia has been trying for decades to tackle its litter problem.

WHYY reports that the 10 new street sweeping trucks can’t fit down 10% of streets in the pilot neighborhoods. The trucks are each 9 feet wide (2.75 meters wide).

Streets Department Commissioner Carlton Williams says the city is considering buying slimmer trucks. He’s not sure how many they would need.

The new fleet of sweepers removes trash blown out from sidewalks and underneath cars by workers sporting gas-powered leaf blowers.

That’s because they city doesn’t require people to move their cars .

Workers have been picking up about 10 tons of litter a week.

(AP)