The effectiveness of Audio Tactile Line Marking (ATLM) is less for heavy vehicles compared to cars. This is because the vibrations through the vehicles are less in the larger vehicles. Truck shoulder rumble strips are an option where the risk of heavy vehicle run-off-road is elevated due to high truck volumes.
When implementing them consider:
- Spacing them to ensure other vehicles are not adversely impacted when using the shoulder/emergency lane
- Delineating them so they are clearly visible for other road users (including motorcyclists)
- Ramp grades and height are sufficient to alert heavy vehicles but not over-destabilise other vehicles.
- Not implementing on tight radius curves where vehicles are likely to require higher traction levels in the run-out-areas
