Nottingham City Council has explained why it only grits just over half of the city’s roads, with heavy snow set to hit the region over the weekend. Out of the approximately 804km of roads in the city, only 445km are covered on a typical grit run, the council has revealed.
The figure represents the “most important” roads in Nottingham, as the council says it would be impossible for its workers to grit all 804km in one night. The roads in question include the ones carrying the most traffic and having the highest risk of accidents.
The authority said: “We have to treat the busiest roads first and once they are clear, keep them clear! These roads tend to be the ones that take most of the overall traffic and the bulk of a typical trip from home to a place of work or the hospital.”
The gritting starts after the council receives a forecast from the Met Office which includes frost, ice or snow. The roads are treated a few hours before the wintery conditions arrive, with a target treatment time of four hours.
All primary routes will normally be treated before the start of the working day and snow clearing will also take place when practicable. Those living or frequenting roads that are not covered by the gritters need not to worry, however, as grit bins are available throughout the city.
They are also placed on footways where there are steep hills, cross falls or which are exceptionally exposed and ice forms more frequently. Currently there are in the region of 200 bins.
And despite being called grit, the winter treatment is actually just salt, lowering the freezing point of the road surface, which subsequently prevents ice from forming. The council said: “Just spreading salt on its own has a small impact but when cars drive over the salt this helps to turn the salt into a brine solution – this is the most effective way of melting and preventing ice.
“When we know that snow is coming, we aim to spread a good layer of salt to prevent the road from freezing and snow settling. Salt itself does not prevent snow from settling but the critical factor is the road surface temperature.
“As each snowflake lands it lowers the surface temperature and it also dilutes the salt solution. This is why heavy snow will settle and then accumulate despite gritting.”
The authority added that traffic plays a key part in the gritting being effective. It said: “Traffic is needed to help work the grit into a brine solution.
“All of our gritting lorries can be fitted with a snow plough at the front to clear settled snow. The ploughs cannot go right down to the surface of the road because this would damage it, so we still need to grit behind us to help the roads to clear.”