The announcement marks the culmination of a two-year National Highways investment project worth £44m with partners including Romaquip to bring the new Volvo vehicles to the national network.
Around 144 vehicles were introduced last winter with the final batch of the remaining 108 vehicles joining them at depots up and down the country by the end of October.
Andy Butterfield, customer service director for Operations, at National Highways, said: “We are delighted the rollout of our new state-of-the-art gritting vehicles is complete, with every machine in position and ready for the winter season ahead to help keep our road users safer on the roads, whatever weather conditions we face.
“The first of these gritters in this £44m two-year investment programme began operating on our roads last year and work has continued over recent months to complete the full set.
“It is testament to the work of our staff and partners to deliver this project ahead of schedule. It was initially going to take three years for the rollout to be completed. It demonstrates excellent collaboration, hard work and a committed and determined focus to deliver every vehicle in time for the 2022 winter period.”
The new Romanquip gritters can travel at a maximum speed of 50mph when salt spreading – 10 miles an hour faster than earlier vehicles – helping to keep traffic moving on the roads during periods of salt spreading.
The vehicles also meet Euro 6 requirements and on-board functions allow salting routes to be uploaded directly into the vehicle cockpit, assisting drivers with the latest information on where and when to salt.
The company said tech advances also enable drivers to choose the most appropriate treatment in different road conditions.
Stephen McKeown, manging director at Romaquip, said: “Realising these innovations in such a large fleet will result in significant measurable enhancement in winter service in the UK.”
Together with the 252 new gritters added over the last two years, National Highways has an overall pool of more than 530 gritter vehicles ready to deploy across the network in sub-zero temperatures if needed, which includes 443 Volvo Romaquip gritting vehicles, all of which have been introduced since the start of the winter 2018 season.