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Road safety

All road users, including truck and bus drivers, are reminded that travelling on the South Eastern Freeway descent into Adelaide requires additional road safety awareness, decision-making and actions.

The South Eastern Freeway ends in a 7km continuous steep downhill descent. Although the gradient becomes less severe near the bottom of the freeway as you approach the second and final safety ramp, it then becomes steeper again and continues downhill through a major, signalised intersection and into an urban area.

Truck and bus drivers should plan their travel down the South Eastern Freeway in advance to ensure they are familiar with the road and the safe driving requirements.

Heavy vehicles pose a greater risk to other road users due to their mass and rigidity, which creates greater impact forces if they are involved in a crash. The speed of a vehicle has also been shown to increase both the risk of the vehicle being involved in a crash and the resulting severity of any crash that may occur. Due to their momentum and mass, heavy vehicles will take much longer to stop than lighter vehicles.

If a truck or bus driver loses control, or has any doubts about arriving at the major intersection safely, they should use a safety ramp. There is no cost to recover a vehicle from a safety ramp on the South Eastern Freeway.

How to descend safely

Trucks and buses can descend safely if the right safety techniques are used from the start of the descent at Crafers and drivers follow signs and traffic controls.

The South Eastern Freeway descent requires all truck and bus drivers to:

  • Engage the appropriate low gear and engine brake at Crafers and remain in this gear to the bottom of the South Eastern Freeway.
    Note, in automatic trucks you must lock the low gear in or switch to manual.
  • Reduce speed to a maximum 60 km/h, unless otherwise signed at a lower speed or your load requires a slower speed, from Crafers to the bottom of the South Eastern Freeway.
    Note, fully loaded trucks will usually descend at 20 to 30km/h.
  • Stay in the left lane between Crafers and the Measdays Bridge.

By using the appropriate low gear and engine brake to control the safe descent speed, truck and bus drivers should not need to use their primary/foot brake, except for brief use to make a gear adjustment.

Truck and bus drivers must not rely on their primary brake as the sole means of controlling the speed of the vehicle. Doing so will overheat the brakes and result in the driver losing control of their vehicle.

Trucks and buses may overtake on the descent as long as they remain in low gear and do not exceed 60 km/h. However, as trucks and buses are required to stay in the left lane between Crafers and the Measdays Bridge exit ramp, they cannot overtake between these points.

Companies and drivers should ensure:

  1. Appropriate training has been completed, and a thorough understanding exists regarding safe driving on steep descents.
  2. The truck or bus is roadworthy, and the brakes and engine brake are functioning properly.

It is important to note that the maximum speed limit for all other vehicles is 90 km/h, unless otherwise signed. Drivers should remember to always drive according to the prevailing road conditions.

Watch the video below to help you prepare for driving down the South Eastern Freeway down-track.

Safety ramps

There are two signed safety ramps on the left side of the South Eastern Freeway between Crafers and Adelaide.

If you lose control, use a safety ramp.

Trucks and buses are encouraged to use safety ramps when they need to.

The Department for Infrastructure and Transport does not charge trucks or buses a fee for using the safety ramps, and even covers the costs of towing heavy vehicles out of the safety ramp.

Safety ramp

The safety ramps are located (see map above):

  1. just prior to the entrance to the Heysen Tunnels; and
  2. just past the Mt Osmond Interchange.

Truck and bus drivers should remember that while the road flattens out on the approach to the second and last safety ramp, it then falls away again. The temporary flatter section of road may lead drivers who are unfamiliar with the South Eastern Freeway to incorrectly think they will be able to regain control of their speed.

If a truck or bus driver who is not in full control of their vehicle attempts to “ride it out” to the major intersection at the bottom of the hill, they will risk serious injury or death to themselves and other road users.

How to use a safety ramp

Safety ramps are very effective in safely stopping a speeding truck or bus. They are the best and safest option for all road users if the truck or bus driver has lost control.

There are clear signs marking the distance to the safety ramps to allow the driver plenty of time to prepare. Clear pavement markings are also in place to indicate which lane to use.

The main stopping force in a safety ramp is the drag caused as the vehicle sinks gently into a bed of gravel. The effect on the driver is less than the use of emergency braking, so the stopping force of the gravel should not result in injury to the driver and is unlikely to cause damage to the vehicle.

The removal of a vehicle from a safety ramp requires the use of tow trucks, however the Department for Infrastructure and Transport does not charge trucks and buses a fee for their removal from a safety ramp or for ramp remediation. The Department for Infrastructure and Transport must be contacted by using the emergency phone at the safety ramp or by phoning Traffic Management Centre on 1800 018 313.

More information

Road sign - long steep descent ahead

Fixed signs can be seen in the lead up to the South Eastern Freeway down-track to alert drivers about the pending descent, provide direction to drivers for how to descend safely and identify where the safety ramps are located.

These advisory signs, as well as speed limit and low gear signs, apply to drivers of trucks and buses. Find information about the definitions of a truck and bus.

Significant penalties apply for truck and bus drivers who do not follow the safe descent laws. Find information about applicable offences and penalties.

The Department for Infrastructure and Transport maintains a number of heavy vehicle checking stations/weighbridges across the State on key interstate networks, including at Monteith on the Princes Highway, between Murray Bridge and Tailem Bend.

These facilities are licensed to the National Heavy Vehicle Regulator (NHVR) for undertaking heavy vehicle compliance activities under the Heavy Vehicle National Law (South Australia) Act 2013 and other specific State laws.

While these sites are shared by some other agencies, they are primarily used by the NHVR and SAPOL for conducting off-road intercepts and inspections, as part of ensuring safe heavy vehicle operation and compliance.

All trucks with a Gross Vehicle Mass (GVM) greater than 4.5 tonnes and buses must enter the sites when the variable signs indicate that all trucks and buses must enter.

Failing to enter the checking station when directed or disobeying a "Trucks and buses must enter" sign may result in a fine.

Variable signs (see example photo below) are situated 400 metres before the checking station and just prior to the station to assist drivers to prepare to enter.

All motorists should be aware that the posted speed limit will be decreased to 80 km/h when the checking station is open and is enforced.

Monteith checking station

Checking Station

The Monteith site consists of two checking stations/weighbridges, situated on either side of the Princes Highway. These Monteith facilities are utilised by both NHVR and SAPOL to intercept and inspect heavy vehicles travelling into and out of Adelaide, principally via the South Eastern Freeway.

The Monteith site is used to conduct a broad range of heavy vehicle safety and regulatory activities, including:

  • roadworthiness and vehicle standards inspections
  • mass and dimensional limits compliance
  • compliance with heavy vehicle driver fatigue and related work/rest requirements
  • ensuring safe vehicle loading and suitable load restraint
  • registration and driver licensing checks.

The Monteith weighbridge has a five-plate weighbridge capable of weighing large combinations, such as B Double combinations, in a single weigh.

The height clearance for the Heysen Tunnels is 5.3 metres (this is also the clearance height for the Mt Osmond and Crafers interchanges).

Over-height warning signs are located before both approaches to the Heysen Tunnels. When the laser beam height detector identifies a vehicle that is too high to travel through the Tunnels safely, the over-height warning sign will flash to direct the driver to stop in the stopping lane on the left of the road.

The laser beam height detector also automatically sends an alarm to the Department for Infrastructure and Transport. Upon confirming the presence of an over height vehicle via cameras, the Department for Infrastructure and Transport will request police or emergency service attendance at the site to assist the driver to turn the vehicle around through a dedicated break in the median strip.

Drivers may also contact the Department for Infrastructure and Transport by using the emergency phones located near the Heysen Tunnels or use their own phone to call the Traffic Management Centre on 1800 018 313.

Each tunnel:

  • is 480 metres long
  • is 10.5 metres wide
  • has three lanes, each lane 3.5 metres wide
  • has a height clearance of 5.3 metres
  • is equipped with emergency phones
  • has broadcast radio and mobile phone coverage
  • is connected by three emergency cross passages to the other tunnel.

Related information

  • Laws, offences and penalties

    Learn about the applicable laws and related penalties to the South Eastern Freeway down-track.