Sheffield Council and highways agent Amey have been accused of ‘fly-tipping’ after leaving cones behind after work.
Amey has resurfaced rural roads in the Bradfield and Ewden areas.
However, traffic cones remain abandoned at the roadside, even though work in the area was completed in autumn last year.
The company is resurfacing every road in Sheffield over the next five years as part of the £2 billion Streets Ahead programme.
Coun Trevor Bagshaw, Liberal Democrat member for West Ecclesfield and a former member of the Peak District National Park Authority, said: “Traffic cones are an essential tool in managing these essential roadworks.
“However, the sight of them carelessly littered across the verges of Sheffield’s beautiful National Park is not a welcome one.
“The council needs to make sure the project runs smoothly and they cannot afford to turn a blind eye to this ‘corporate fly-tipping’.
“I would urge anyone finding abandoned cones or other highway works equipment to contact the council and ask for them to be collected.”
The council said it was investigating Coun Bagshaw’s complaints.