Speed limits are carefully calculated to represent the fastest possible speed a person can safely drive through a specific area. Speed limit values are usually determined by driving experts, engineers and topography professionals to reduce the risk of accidents resulting from driving off-road.
These limits also help both new and experienced drivers know which speeds are appropriate for safe road navigation. Whether they are negotiating a sharp turn, road tunnel, narrow road, limited-visibility hill or any type of road, adhering to speed limits ensures the safety of the driver, other motorists, pedestrians, animals and structures.
Understanding speed limits in Western Australia
In Western Australia, the agency in charge of setting speed limits is the Main Roads WA or MRWA.
MRWA engineers consider certain factors, such as general topography, road design and urban density, in calculating the speed limit in a specific area. This is why speed limits in WA vary, especially since there are certain places that are densely populated whilst others are not. Therefore, it’s safe to say that speed limits on Perth roads would be a little different than along major highways like the Indian Ocean Drive.
Also, speed limits may vary depending on the type and gross weight of the vehicle, so caravan speed limits in WA are usually different from those that apply to cars.
Speed limits for learners and newly qualified drivers
In WA, the highest speed zone (open or outside metropolitan areas) is 110 kilometres per hour. Experienced drivers are advised to drive to posted speed limits. For learner and provisional drivers, however, there are certain restrictions that apply.
- L Plate Speed Limit: The maximum speed for learners in WA or L plate speed limit is 100 kilometres per hour.
- P Plate Speed Limit: For provisional drivers, the maximum or P plate speed limit in WA is 100 kilometres per hour – similar to professional drivers. However, provisional driver’s licence holders are usually not allowed to drive from midnight until 5am for the first six months of holding a driver’s licence.
Speed limits in WA by road type and zone
Since there are different road conditions and settings all across WA, it follows that there would be variations in the speed limits based on the road type and zone.
- Highway speed limit: The default speed limit in non-residential roads in WA is 110 kilometres per hour unless otherwise posted.
- Freeway speed limit: Unless zoned differently, the default speed limit for freeways is 100 kilometres per hour.
- Rural interstate highway speed limit: The speed limit in rural areas in WA is 110 kilometres per hour, except when indicated differently.
- The speed limit in built-up areas: In general, the speed limit in built-up areas is 40 kilometres per hour. However, the default speed limit for built-up areas where no signs are displayed is 50 kilometres per hour.
- The speed limit on roads outside built-up areas: The default speed limit is 110 kilometres per hour for open areas or roads outside built-up areas.
- School zone speed limit: Permanent 40 kilometres per hour speed limits usually apply on some roads outside schools. Some speed signs outside schools may also display time-based or scheduled speed limits.
- Shared zones: The speed limit in WA shared zones is 10 kilometres per hour.
How to check the speed limit on a road
If you want to know how to check the speed limit on a road, there are a number of ways by which you can do this.
Speed Limit Signs
The most reliable way of checking the applicable road speed limit would be to refer to speed limit signs such as the ones below.
Sign Name: MR-RS-1 (WA Maximum Speeds)
You may see this sign near the boundary of a metropolitan area where the default speed limit can change from 50 to 110 kilometres per hour. It is also used along main roads going into WA from neighbouring states or territories.
Sign Name: MR-GE-22 (Start of Freeway)
The MR-GE-22 is used as a supplementary plate in combination with a Speed Restriction sign (R4-1) as an indicator of the start of freeway conditions.
Sign Name: R4-10 (Area Speed)
Area speed signs (R4-10) are utilised as repeater speed limit signs. These are installed within a speed-limited area with around 500-metre intervals in between each continuous street longer than 1,000 metres or one kilometre.
Sign Name: R4-11 (End Speed Limit Area)
The END Speed Limit AREA sign is placed on both sides of a terminating road, back to back with the Speed Limit AREA signs or R4-10.
Sign Name: MR-RS-7B (School Zone)
The MR-RS-7B school zone sign applies to all WA regions except the Northern Regions. It is used to indicate a school zone speed limit of 40 kilometres per hour in all parts of WA where the speed zone outside of school hours is 50, 60 or 70 kilometres per hour.
Check the police website
Perth speed limit map
You can also refer to a Perth speed limit map like the one below. Just make sure to type the applicable filters to narrow down your search.
New vehicle technology
Some new car models use their built-in GPS navigation and map data to pull speed limit data from servers and display it on your dashboard. Tesla cars with a built-in autopilot system can now recognise speed limit signs using cameras after a software update late last year.
The 2020 Lincoln Aviator luxury SUV’s intelligent cruise control feature enables the vehicle to read speed limit signs and adjust the speed accordingly. The second-generation Ford S-Max launched in 2015 also features a speed limiter that can read signs and modify the speed as needed.
When are you allowed to drive above the speed limit?
WA and the rest of the country take over-speeding offences seriously. But if you’re wondering if there are instances when you are allowed to drive above the speed limit, there may be exceptions to the rule.
Exceptional cases where you might have been speeding because you were driving a dying passenger to a hospital or fleeing a disaster such as a bushfire or a tornado may be given some consideration.
However, to know for sure, it’s best to seek legal advice.
Speeding penalties in WA: What you need to know!
Speeding penalties in WA come in the form of fines and demerit points. Fines range from $100 to $1,500 with matching demerit points depending on the vehicle type and the number of kilometres per hour over the speed limit.
Speeding by light vehicles such as cars and motorcycles with a gross combination mass (GCN) that’s less than 22.5 tonnes have a different set of fines and penalties from heavy vehicles.
For example, if you drive over the speed limit by no more than nine kilometres per hour, you’ll be fined $100 ($200 for a heavy vehicle) and get zero demerits. However, if you go over the speed limit by more than nine kilometres per hour but less than 19 kilometres per hour, the fine increases to $200 ($300 for a heavy vehicle), plus you get a 2-point demerit.
However, if the act of over-speeding leads to severe injuries, damages or death, you are likely to face more serious consequences beyond fines and demerits.
Drive safely: Do the right thing
When it comes to the law or rules, including those governing speed limits, ignorance is not an excuse.
Therefore, it’s important to familiarise yourself with road safety rules early on, especially while learning to drive. Driving lessons and driving tests are designed to help you develop an understanding and mastery of these rules, so make the most of your time as you learn to drive defensively and responsibly.
Frequently Asked Questions
The maximum speed learner drivers can travel is 100km, even when travelling in faster zones. This law is in place to give inexperienced drivers the ability to develop their reaction to traffic before driving at a rapid speed.