GPS-controlled gritting: route, rate and width by position

Statens vegvesen (the Norwegian Public Roads Administration) writes that GNSS-assisted gritting can be an effective aid on routes with complicated traffic conditions, and that it is best suited to anti-icing with salt solution where the whole area is to be treated.

How it works

Falköping writes that the software in the Panel PC lets you programme the routes to be driven in advance. The program then controls rate, width and symmetry automatically, and while driving, the driver gets route guidance both visually and by voice. According to Falköping, this lets the driver concentrate on the traffic.

Statens vegvesen's textbook on winter maintenance describes the principle like this: the system was originally developed in Denmark and uses satellite positioning to control the application of spreading material according to where the vehicle is. At bus bays, turning lanes, varying numbers of lanes and roundabouts, the system can give more precise spreading without the driver having to adjust the rate, width or symmetry. On complicated routes in built-up areas, the spreader may need between 200 and 500 adjustments.

In the course material for operators, Statens vegvesen writes that the technique is used on the entire Danish national road network and in most Danish municipalities. In Norway it has been tried out in the maintenance contracts in Stavanger from 2011 and Bergen from 2015, and in Romerike øst.

The control system it builds on

The GPS control builds on the Panel PC control system. According to Falköping, it has infinitely variable, synchronised setting of width and rate, spreading that follows the driving speed, feedback-controlled feed augers and a quantity counter. It is calibrated with a built-in tacho function and is prepared for data collection, GPS and GSM transmission, control according to road surface temperature and external communication using the CEN/DAU protocol. For the tractor spreaders in the TC series, the 2026 brochure specifies the C-365 control system or Panel PC.

Where it is suitable, and where it is not

Because the current system requires a pre-programmed, fixed driving route, Statens vegvesen writes that GNSS-assisted gritting is best suited to anti-icing with salt solution where the whole area is to be treated. Allow about one day's work per gritting route to programme and adjust the system. If you will be using salt solution, see the liquid spreaders and the guide Winter maintenance: dry salt, pre-wetted salt or brine?.

• Well suited: routes with complicated traffic conditions or many changes in width and rate, and preventive treatment with salt solution
• Less well suited: anti-compaction together with ploughing during snowfall. The driving pattern varies, especially at junctions, and the GPS cannot distinguish the lanes on multi-lane roads
• In all cases: snow and slush must be removed mechanically before salting

Does it save salt?

Falköping writes that the correct width and symmetry reduce the amount spread. Statens vegvesen is more cautious. The speaker's notes for the course on gritting equipment say “Lower salt consumption? Not necessarily”, but that the quantity and placement of the spreading material are more accurate, with reference to VTI report 791 from 2013. The experience from Stavanger was a sharp increase in the use of salt solution and a corresponding decrease in pre-wetted salt.

A Swedish VTI report from 2021 assumes that less salt ends up off the road when the spreader is controlled automatically, and reports that spreader manufacturers state an average salt reduction of around 8–10 per cent. The figure was not measured by VTI.

Statens vegvesen also highlights safety. Both as driver support and as a contribution to improved road safety, the textbook calls GNSS-assisted gritting a good health, safety and environment (HSE) measure.

What documentation the maintenance contracts require

The course material Statens vegvesen uses for its maintenance contracts (2025) describes these requirements for reporting and documentation. The requirement for automatic data collection applies to quantities included in the quantity-based settlement, typically ploughing, ice planing and gritting on the European and national road network:

• Quantities used and carried out in winter maintenance are reported on form R12 in Elrapp
• Quantities included in the quantity-based settlement are also documented electronically in Elrapp via automatic data collection, and discrepancies between the two must be explained
• A salt log must be kept documenting the assessment and decision for every salting operation
• Gritting must only be logged when the spreader is actually spreading, and spreading width and dosage must also be reported electronically
• Which production types are to be recorded, and the data format, are set out in contract appendices D2-IC0842a and IC0845a

Data from the spreader

From large spreaders with automatic data capture (Falköping is mentioned among them), the data capture system retrieves the spreading material, rate, width and sector from the spreader's control console and accumulated quantities from the counter. For spreaders without data capture, the stretch is tagged as gritting. The course material mentions two ways of obtaining the quantity: the total quantity spread is entered manually when the operation is finished, or a predefined quantity in g/m² per vehicle is entered, which the system converts according to the distance. The 2026 edition of the textbook has largely removed the contract-specific requirements from the text, so check the requirements in your own contract.

Falköping's data collection provides a running history of all actual values controlled from the control panel. It can be supplemented with GPS for automatic road identification, and transmission from the spreader can be via GSM. See also BM System and Smartbox and Forecast-controlled gritting.

Calibration and common faults

According to the textbook, the spreader must be calibrated before each season and checked, and recalibrated if necessary, at least once a month during the season. It must also be checked or calibrated with each new delivery of spreading material and when it is mounted on a new carrier vehicle. The calibration must be documented and reported to the client.

The course material mentions these common causes of missing or incorrect data. The first three apply to large spreaders, the last applies to data capture in general:

• The cable from the control console is not connected to the data capture unit, or the wrong cable has been used
• The speed signal is not connected to the spreader's console, or it is not calibrated for the spreader make
• The spreader is not calibrated for the spreading material being used
• Poor satellite coverage causes “drifting” and GPS jumps, so that points end up outside the contract road network

Before you order

Have answers to these questions before you choose a control system:

• Which routes are to be driven as a fixed route, and are they treated with salt solution, pre-wetted salt or both?
• Who programmes and adjusts the routes, and when?
• Which data capture system is the spreader to be connected to, and which data format does the contract require?
• Who calibrates the spreader and the speed signal, and who reports the calibration to the client?

Ask us

If you have questions about Falköping's control system and data collection, you can contact us.