Road damage forces rider rethink

Heavy trucks can cause massive road damage

Heavy trucks create so much road damage on our roads that motorcycles are forced to amend their safe cornering lines and road position.

Trucks create corrugations under braking, ruts in the road from their heavy loads, and leave oil and diesel in the centre of the lane. These hazards are more common on rural roads that are not well constructed and are populated by heavy livestock and grain trucks. However, I have also seen ruts and corrugations on our major highways. These hazards are all potentially dangerous traps for motorcycles, made worse by rain.

Heavy trucks can cause massive road damage
Rutted outback road

The common theory is to follow the wheel tracks in the rain to avoid the oil and diesel in the centre of the lane. This is true if it has just started to rain after a long dry period. This causes the oil and diesel come to the surface and make the centre of the lane very slippery. However, with more rain, it washes into the ruts created by truck wheels, where it pools and makes it even worse for traction. On the approach to corners and roundabouts, wheel tracks can also become corrugated by a truck’s skipping wheels under brakes. These will cause your back wheel to hop and reduce your bike’s braking performance.

In some instances, the best course is to ride wide of the wheel tracks, either toward the centre of the road or the outside, although you can encounter other hazards here such as broken road edges, gravel or oncoming traffic.  In the wet, it’s best to slow down and use your eyes to scan the road surface for standing water, corrugations, potholes, ruts and rainbow colours that suggest oil and diesel spills. You can sometimes even smell the diesel, but often it’s too late and you are already in it.

Trucks also make cornering difficult for bikes. The usual practice is to turn in from the outside of a bend, clip the apex and then run wide on exit. However, if the road is rutted by trucks, it results in the rider running in and out of the wheel tracks while leaned over, which can cause instability. When the road is wet it also means your will be riding in and out of slippery areas.

The safest practice in heavily rutted corners – wet or dry – is to stay in the right wheel track for left-hand corners and vice-versa. This means you are not crossing the slippery centre part of the lane and not going in and out of the ruts. The outside wheel track also has the wider arc through the corner. On left-handers it keeps you further away from gravel that may have washed on to the road surface or been dragged on to the road by vehicles dropping a wheel off the edge. On right-handers it is the cleaner wheel track as trucks and cars often cut corners, dragging their sump oil leaks across the right wheel track. The reverse is true in countries where they drive on the right.

It’s not the quickest way through a corner, but it could be the safest way on roads that have been damaged by trucks.


  1. If only the surface was the only hazard confronting riders then riding would be easy, although I’m sure some people would still find a way to crash. But let’s just look at what you are suggesting on both left and right turns and ask have you considered all the hazards. Firstly on the lefts this will place you very close to oncoming traffic and certainly in the “head on zone” but even worse if the corner tightens more than expected you will find yourself on the wrong side of the road. Secondly for the rights, whilst this keeps you well away from the “head on zone”, and again it the corner tightens more than expected you will at best be off with “Blinky Bill” gathering gum leaves. Both scenarios could end up in much worse results which is the reason the are not taught in current rider training. The apex, which also runs wide, is again not considered best practice in Roadcraft.

    Current teaching is along the lines of OBSERVATION. This is more than just seeing things. It involves actively looking and scanning for any potential problem or hazard and perceiving the situation as something that requires action by the rider – a minimum of 5 seconds ahead. Where you place yourself, and at what speed and gear, is more on your assessment of the hazards and risks rather some hard an fast rules.

    1. Thanks for your comments. Unfortunately road craft courses rarely are held on “real world roads”. Road craft courses on circuits can only ever have limited value. You are absolutely right that you have to scan for obstacles and choose your lines accordingly. And obviously you have to adjust your speed so you don’t run wide.

      1. Roadcraft is conceptual learning and it depends on the riders ability to transport the knowledge to the situations encountered. Many courses, and indeed the licencing progressions in Qld & NSW, are conducted on “real word roads”. Most of the circuit courses are really addressing the basics that unfortunately so many licenced riders lack.

          1. Not only did the GCCC pull the programme but they pulled all record of it from their website so now no history is available. Apart from a couple of odd shirts you may see from time to time or the mention of an award in some obscure Google search, it’s as though it never existed. I wonder if anybody remembers the Road Safety Council of Queensland and the Motorcycle Training Programme? Perhaps that a little too long ago. Maybe somebody still remembers that attempt to stop crashing prior to the SMART initiative!

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