Winter maintenance

Maintenance category Ise

(1,671 km: 2% of road length, 33% of traffic, 29% of heavy traffic)

The road is mainly uncovered. Snow removal starts once snowfall begins. Slipperiness is prevented in advance. The aim is to keep the road always in the condition defined in the quality requirements. The time allocated to snow removal is a couple of hours. When the weather changes, some slightly slippery conditions may occur. During long periods of subzero temperatures, when salting is not possible, the road surface may also be icy in places. Maintenance rounds on maintenance category Ise roads are short, so that busy roads can be quickly maintained to the condition defined in the quality requirements.

Maintenance category Is.

(7,882 km: 10% of road length, 36% of traffic, 41% of heavy traffic)

The road is mainly uncovered. Snow removal starts soon after snowfall begins. Slipperiness is mainly prevented in advance. When the weather changes, some slightly slippery conditions may occur. During long periods of subzero temperatures, when salting is not possible, the road surface may also be icy in places. The time allocated to snow removal and anti-skid treatment is a couple of hours. Maintenance rounds on maintenance category Is roads are fairly short, so that the maintenance round can be completed in the time allocated.

Maintenance category Ib

(9,956 km: 13% of road length, 15% of traffic, 15% of heavy traffic)

Most of the time, the road is mainly uncovered, but in subzero temperatures, there may occasionally be low and narrow lines of packed snow located between the carriageways and between the driving ruts. The aim is to keep the packed snow thin with the fast removal of loose and packed snow. Anti-skid treatment is mainly done by salting. The aim is to prevent slipperiness in advance. During long periods of subzero temperatures, when salting is not possible, the road surface may be icy in places. Slippery conditions that may occur during subzero temperatures are prevented by gritting, as necessary. The time allocated to snow removal and anti-skid treatment is a few hours.

The contract tendering process will involve a transition to the use of operating methods that ensure that there will be hardly any roads covered entirely with packed snow.

Winter maintenance category Ic

(5,835 km: 7% of road length, 6% of traffic, 6% of heavy traffic)

The road is usually partly covered with packed snow and sometimes or completely covered with packed snow. The ruts and surface of the packed snow are levelled as much as possible. The road pavement condition and road edge depressions affect the levelness of ploughing. For the most part, anti-skid treatment involves point and line gritting and the roughening of packed snow. In winter conditions, traction is not good at all points, which should be taken into account in driving behaviour. The occurrence of black ice is also prevented by salting. Especially in the autumn before actual winter conditions and in the spring when subzero temperatures occur at night, anti-skid treatment is done by salting. Salting can also be used in anti-skid treatment at other times if the conditions are favourable. The time allocated to snow removal and anti-skid treatment is a few hours. The intensity of snowfall affects the time when ploughing starts.

Maintenance category II

(15,511 km: 20% of road length, 6% of traffic, 6% of heavy traffic)

The surface of the road is mostly covered with packed snow and there may also be ruts in places. It may snow several centimetres before maintenance procedures are started. In the newest contracts, the procedures will be started a little sooner than this in the period between 2 a.m. and 8 p.m. Road surfaces are roughened and the intersection areas, hills and curves are gritted regularly. During the most problematic road conditions, the roads are also gritted completely. The need for gritting is determined according to the conditions. The road network’s ploughing and anti-skid treatment routes are long, which means that they take several hours to drive through.

In normal situations, the road has sufficient friction and smoothness for moderate traffic. In difficult weather conditions, such as during a sudden rise in temperature or immediately after snowfall, caution is required from all road users.

Maintenance category III

(37,020 km: 48% of road length, 4% of traffic, 3% of heavy traffic)

The road surface is covered in packed snow most of the time and there may also be ruts in places. The quality level is mostly the same as on maintenance category II roads, but snow ploughing may take up to one hour longer and anti-skid treatment up to two hours longer. A little more snow is also allowed than in the maintenance category II. When the weather changes, the road conditions can be problematic for several hours, which means that extra caution must be taken when driving.

Pedestrian and cycling routes

Maintenance category K1

(3,277 km: 53% of pedestrian or cycling route length)

In winter conditions, pedestrian and cycling routes are mainly covered with packed snow. Anti-skid treatment procedures start within two hours. Slipperiness on pedestrian and cycling routes is prevented by gritting or roughening. There may be a few centimetres of loose snow on pedestrian and cycling routes before maintenance starts routes paths must be ploughed within three hours of the start of maintenance. At night between 10 p.m. and 6 a.m., quality may be lower but the surface of the route must still be safe.

Maintenance category K2

(2,694 km: 44% of pedestrian or cycling route length)

In winter conditions, pedestrian and cycling routes are mainly covered with packed snow. The quality level is mostly the same as on maintenance category K1 routes, but snow ploughing and anti-skid treatment may take up to one hour longer. At night between 10 p.m. and 7 a.m., quality may be lower but the surface of the route must still be safe.

Maintenance category L

(171 km: 3% of pedestrian or cycling route length)

The route-like quality corridors for pedestrians and cycling are located in major urban areas. The requirements for quality corridors are defined on a case-by-case basis so that they are consistent with the cycling route network in the municipalities on the quality corridor and the requirements are in some respects higher than in the maintenance category K1. For instance, the slipperiness of the quality corridor may be prevented by brush salting, the allocated times may be shorter or in the spring, grit may be removed from the quality corridors earlier to promote cycling. Quality corridors may also have night-time quality requirements.

During snowstorms, the quality requirements are not valid

Maintenance contracts are dimensioned according to normal weather conditions. In the winter, weather conditions may change rapidly, making it very difficult for the maintenance contractor to be responsible for road maintenance according to the quality requirements. During heavy snowfall (10 cm in 4 hours) or during rain of supercooled water, roads fall below the quality requirements quickly after maintenance. In these situations, the quality requirements defined in the maintenance categories are not valid. The contractor will work continuously with all their fleet. Roads will be maintained to their normal condition when conditions return to normal.

Clearing the view at junctions

The safe use of junctions requires a clear view. Near junctions, any snow banks blocking the view are lowered and other obstructions limiting visibility and posing an immediate danger to traffic are removed as soon as possible. Views at junctions are continuously maintained.

The maintenance of views at junctions is not the responsibility of the road maintenance contractor alone: junctions to public roads fall under the responsibility of the road owner, which can be the state, a municipality, a private road cooperative or the owner of the property. 

With regard to snow banks, see also