Measures to prevent crashes involving agricultural vehicles, are targeted at 1) the vehicle, 2) the road and the place on the road occupied by agricultural vehicles, and 3) the driver. Below the measures in the first two categories are discussed. The measure aimed at the driver – the introduction of the T-license – is discussed under the question What is the road safety effect of the T-licence? .
Because we have only limited insight into the causes of crashes involving agricultural vehicles, it is difficult to estimate the exact effects of the various measures.
Vehicle measures
Technical requirements and testing
Legal requirements for all types of agricultural vehicles and a (periodic) inspection should contribute to improved vehicle safety: the Dutch Safety Board made this recommendation in 2010 [2]. There are already European requirements for tractors that participate in traffic on a certain date or will participate after that date. Because these vehicles are not registered and licensed in the Netherlands, monitoring is not possible.
Safety features for agricultural vehicles
Safety features for agricultural vehicles are not always easy to achieve. Agricultural vehicles are primarily designed for use on farms and in fields. According to the Vehicle Regulations (in Dutch) any sharp parts that could cause injury to road users, must be screened off before entering the public road. Where additional measures have been taken or developed, this was mainly done on the initiative of the sector. For example, NAM, whose core business is exploring for and producing oil and gas in the Netherlands, demands in contracts with their subcontractors that tractors (and trailers) are equipped with shielding facilities for the front, side and back. The so-called tractor bumper (shielding device at the front) is mainly intended to limit the consequences of crashes with a car. NAM also makes demands concerning maintenance, lighting, retroreflective side and contour marking, and age and experience of the driver.
Behl et al. [17] argue that especially equipping agricultural vehicles with a Lane Change Assistant (LCA)[i] has a high safety potential: a 21% reduction in serious casualties. According to these researchers the potential effect of measures that improve the visibility of agricultural vehicle and trailer (retroreflective marking at the rear, anti-glare headlights, clear taillights, contour lighting, etc.) would be a 17% reduction in serious casualties, and that of front and side under-run protection for trailers would be a 7% reduction [17].
Infrastructural measures
Structural area-specific solutions
The most appropriate place on the road for agricultural vehicles is not easy to determine, with regard to the Sustainable Safety-principle of homogeneity of speed ánd of mass (see also the question What is the safest place on the road for agricultural vehicles? and SWOV fact sheet Sustainable Road Safety).
Preferably, the land management and the organization of farming should be such that agricultural vehicles need to use the public road as little as possible. In this context Jaarsma, Rienks & Hermans [12] point out the possibilities of trading agricultural lots and adjusting the structure of rural roads, making agricultural lots exclusively accessible via access roads. Based on calculations with a network model, Hospers et al. [18] conclude that increase of plot size by reallocation of land reduces the agricultural traffic on public roads.
In Advancing Sustainable Safety, Wegman & Aarts [19] advocate the use of dedicated lanes for trucks as a solution for the issue of freight traffic. Similarly it can be reasoned that in the long run agricultural vehicles do not belong on the public road at all, but should be on a special vehicle lane. An example of this is in the municipality of Tholen in the Province of Zeeland where in 2012 an agricultural path was introduced that leads agricultural traffic around the village centre [20] [21].
Short-term solutions, road section related
In the short term, road section-related measures can also contribute to improved safety of agricultural traffic in addition to these structural, area-specific solutions. On roads where agricultural traffic mixes with cyclists and pedestrians it is important to reduce speeds on road sections (but at intersections as well). According to the homogeneity principle is not advisable to allow agricultural vehicles on distributor roads (with a speed limit of 80 km/h) in view of the speed difference with the ordinary motorised traffic. On these routes a service road would be more appropriate. However, given the speed difference as well as the differences in mass and structure between agricultural vehicles and cyclists it is equally inadvisable to allow these two modes of transport to mix on service roads [22]. A possibility to prevent this is the construction of a bicycle path in two directions at one side of the main road and a service road in two directions for agricultural vehicles at the other side.
Another option is to allow agricultural vehicles on distributor roads – possibly with a higher permitted speed plus making higher demands on vehicle and driver. According to Sustainable Safety a road with a speed limit higher than 70 km/h should have direction separation that is hard or impossible to cross. It is important that at such roads so-called ‘passing places' are constructed or that there is the opportunity, for example, before or after intersections, to overtake agricultural vehicles. Such an option can reduce the delay for other traffic and therefore presumably also reduce irritations [23] [24].
Finally, the Dutch Safety Board suggests the construction of left-turn lanes in accordance with the Handboek Wegontwerp [25] (Manual Road Design) as a measure to prevent lateral and rear-end collisions on distributor roads [2]. Furthermore, Behl et al. [17] mention improving the view from yard or field as a measure to prevent lateral conflicts when the agricultural vehicle enters the road (approximately 5% reduction in serious casualties).
[i] Lane Change Assistent (LCA) helps the rider to change lanes safely. The system monitors the space next to the vehicle including the blind spot. When the driver has activated the direction indicator, the LCA gives feedback (usually through an acoustic and visual signal) on whether the adjacent lane may or may not be free.
