Herefordshire Council’s environmental health and trading standards service, in partnership with the Vehicle and Operator Services Agency, stopped 50 vehicles on Edgar Street in April and 48 vehicles in Ross last week.
Exhaust emissions were examined to ensure they meet stringent new MOT standards while routine road safety checks were made on tyres and lights.
In Hereford, three drivers were served prohibition notices for serious mechanical road safety defects.
In Ross-on-Wye, six drivers were also served with notices for defective tyres, with one notice served for a car with windows so dangerously tinted that it affected the vision of the driver.
Seven fixed penalty notices were also served for other matters, such as not wearing a safety belt.
Officials are warning against complacency and have stressed that a series of random spot checks will continue throughout the year to ensure high standards.
Andrew Tector, head of environmental health and trading standards, said: “As both the A49 in Hereford and the A40 corridor near Ross-on-Wye are recognised as having poorer air quality, these checks will help protect the local community from high levels of pollution by ensuring that vehicles driving in these areas are running as cleanly as possible.
“As well as the obvious benefits of this exercise to air quality, Herefordshire Council also has a role to play in promoting road safety and we will therefore continue to support the work of the Vehicle & Operator Services in this important area of their work,” he added.
Councillor Brian Wilcox, Herefordshire Council's cabinet member for highways and transportation, said: “I believe spot checks can actually save people’s lives while also raising awareness of road safety issues such as driving a vehicle with illegal tyres.
“It is a known fact that worn tyres work less efficiently and affect the braking performance and cornering of a vehicle. Worn out tyres cost lives. I am also both surprised and disappointed that some drivers are still neglecting to wear a safety belt, even on the shortest of journeys, as many accidents happen just a mile or two from home,” he added.
Statistics show vehicle emission failures are improving although road safety defects such as worn tyres and defective lights are still recurring.
Future random spot checks on vehicles including cars, vans and taxis will be repeated throughout the year.