Ask LH: Can You Speed Up To Match Speed Limits Before You Pass The Sign?

Ask LH: Can You Speed Up To Match Speed Limits Before You Pass The Sign?

Dear Lifehacker, Is it legal for me to begin acceleration when a speed increase sign is visible or does it have to be readable? I drive on the Mitchell in Perth five days a week taking the same route. I start in an 80 zone and know exactly where the increase to 100 sign is. When that spot is visible I begin acceleration.

Recently I received a speeding ticket from about 80 metres past that point. In the photo below, my car is parked about 20M behind the point where the radar gun was used. Any thoughts? Thanks, Speed Off

Speed limit picture from Shutterstock

Dear SO,

Sorry to be the bearer of bad news, but you’re 100 per cent in the wrong here. Contrary to popular belief, it’s illegal to start accelerating when a speed sign becomes visible. It’s also illegal to start accelerating when the numbers are readable.

In short, you’re supposed to wait until after you pass the sign; never before. The WA Department Of Transport safety handbook spells out the rules pretty clearly:

You must not exceed the legal speed limit for the road or area in which you are driving.

This is one of those road rules that motorists tend to ignore and most traffic police turn a blind eye to. Nevertheless, it’s still the law and you were unquestionably in the wrong by speeding up prematurely.

There’s a small chance a judge will take pity on you if you decide to contest the fine in court. Your chances of success will depend on your driving record — having no previous infringements will definitely work in your favour, especially if you’ve been driving for many years.

With that said, I wouldn’t get my hopes up. At the end of the day, the fault was entirely yours. The fact it’s an illogical law that most motorists break is unfortunately irrelevant. Rules are rules.

Cheers Lifehacker

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  • The fact it’s an illogical law that most motorists break is unfortunately irrelevant
    How is it an illogical law though? The sign tells you what the speed is past that sign. When I am driving interstate and see the sign for the border crossing, I don’t assume I am somewhere else already…
    Or have i misread the above quote?

    • +1 – there’s nothing illogical about it – assuming that somehow there is a magical radius around the sign with no visible or recognisable indicator, but within which the new speed limit mysteriously applies? Now that’s illogical.

    • It’s illogical when the road conditions are identical directly behind the sign and it’s only a question of a few metres — the positioning of speed limit signs is hardly an exact science, after all.

      In some cases, it can actually be more dangerous to enter a high-speed road while travelling at the previous speed limit. (Obviously, residential areas are different but the OP was referring to a freeway fine.)

      • The sign marks the beginning of the zone the speed limit it displays applies to. You could argue about the logic of where the sign was placed, but the logic of the law itself is impeccable.

        As for road conditions, I respect that good drivers can feel the conditions for themselves, but there are plenty of conditions drivers can’t readily see, like dips and weak surfaces. There’s a fair bit of science (doesn’t have to be exact) involved in determining appropriate speeds under conditions that state road agencies have an intimate knowledge of, and a whole lot of statistical data on accident rates at different speeds. Second guessing that research because at a cursory glance it looks safe doesn’t seem very logical.

      • I see your point.

        However, road signage is dictated very clearly and precisely by handbooks used in each state. The handbooks don’t provide leeway for permanent and temporary signage, whether installed by the government or contractors. Seemingly illogical signage, especially during roadworks, has very specific rules. Most of the reduced speed limits are due to reduced shoulders – the dreaded reduction from 110 to 80, even when there are no workers around.

      • It’s not illogical at all. Illogical would be saying “speedup when you can read the sign” for a sign that’s in the same place every day and is entirely memorisable by even the dimmest of drivers. There has to be a demarcation line somewhere, and right at the sign is the only logical place.

    • Now imagine the other way round. Ur traveling on a road which is 100kmph & leads out to a road at 70kmph. As the logic I should be pressing my brake pedal only after I reach the sign board of 70kmph until then cruise and if I fail to reach 70 then take a ticket for that too or create a pile up behind me in trying to do so

  • As a fellow Perth driver, I feel your pain. There’s a spot when you’re getting onto the Kwinana Fwy southbound from Canning Hwy where it’s 60km/h for about 200m before changing straight up to 100km/h on the freeway. Most people don’t do 60 there because its for such a short distance and you need to get up to speed before reaching the freeway. But that doesn’t stop the occasional cop camping at that spot to fine all the “speeding” drivers. Ridiculous.

    • Mate same problem as getting off the freeway and rapidly decelerating. That last lane is usually slow from south tce exit.

      First world problems.

  • Holy shit, no wonder the country is headed for mass stupidity with Ask LH stuff like this.

    • If you got booked for something trivial like this, you wouldn’t ask others what they thought?

      Questioning something that isn’t such a common thing does not make one stupid.

      I also agree that on freeway onramps many cars need to start accelerating early to be able to match the flow of traffic. My local onramp is so short that this is the case.

      • Nope, I wouldn’t. Because I’m not stupid and I know what speed limit signs mean.

        I must also point out that I managed to turn this computer on, all by myself!

      • Probably a good case for mandatory license re-testing, if one has forgotten the most basic of road rules.

        • It concerns me that the vast majority of these Ask LH questions (at least recently) have to do with traffic offense fines and how to get out of them.

          • Was thinking the same thing. Maybe they need to start a Roadhacker site ?

          • Dear Lifehakcer,

            I got pulled over for doing a bad thing and then when the police was telling me that i did a bad thing i putted my hands over my ears and went LA LA LA LA LA LA and that means that it dosen’t count because i didn’t hear what he was saying.

            Now they are making up rules like wtf they said I have to go to court.
            Does putting my hands over my ears and going LA LA LA LA LA LA count in court the same way is if when a police office pulled me over?

            -You’re average Lifeahcker question-asker

      • No harm in it, people get their wires crossed pretty easily. Might’ve been thinking about the suggestion that some instructors give to start slowing when you see a speed limit, to get you into the habit of decelerating slowly.

        • No, they ask you to start slowing before you reach a speed limit sign so you don’t break the law when you go past it. If you’re in in an 80kmph zone and the sign up ahead says 60, you have to be traveling no faster than 60kmph as your front wheels go past that sign. So unless you can go from 80kmph to 60kmph in the space of one mm without getting a head injury as your brain slams into the front of your skull, it is wise to slow down a little way before the sign.

          Why on earth would laws say things like “when you read the sign start speeding up” or “after you go past the sign start slowing down”
          That leaves it open to interpretation.
          Eg: “no officer I wasn’t speeding, I read the sign through my telescope a few km back so I accelerated up to 100kmph”
          “no officer I wasn’t speeding through the town centre, I saw the 60kmph sign and have been slowing down ever since. I was doing 80kmph just before it and 10 minutes later when you saw me I had already slowed down to 77.4kmph”

          As it has been said before, if you are stupid or don’t have basic logic skills, might be time to take your driving test again.

          • Would be hilarious to have police following you in traffic as you cross from 80 to 60 and slam on the brakes sharply so as not to speed in the 60 zone.

      • Here at my freeway on-ramp (Freeman’s Waterhole, NSW) there’s a 110km/h speed limit at the start of the 300-metre down ramp so one can accelerate up to match the road speed of the users on the freeway.

        Nothing 5h1t5 me on the freeway quite as much as low speed merging cars coming in slowly from on ramps and not already being ‘up to speed’.

  • The nearly arbitrary fluctuation in sign-posted speed limits can make it quite difficult to obey them. All you need is one truck on the inside lane that obscures a speed change sign (hello Parramatta Road and Princes Highway) and you’re down $100-200 bucks.

    I tried leaving my GPS device on all the time, but even with regular updates, the speed limit information is usually wrong by 10-20kph (up or down).

    • Yep I agree with this, Ive often thought that it would be good to have different lines on the road that denote different speed zones so its easier to keep tabs on when you miss a sign (colours, markings etc). But this would of course be quite difficult to implement, especially with zones that tend to change due to roadworks etc). I often miss a sign and wonder what speed zone Im in.

  • And the reverse is also true? In that you have to slow down BEFORE the sign, so as not to be exceeding the limit when you are in line with the sign?

    • greenlego, the answer to your question is that yes it is absolutely true. If a police officer was to be performing speed checks at that exact point, they could fine/demerit you as soon as you were 1mm into that speed zone and had not decelerated to the correct speed by the time you passed the sign.

      • I had a friend argue that you had until the next speed sign to slow down to the speed limit…

    • correct. each speed limit zone starts and ends at each sign. you need to be doing below the speed limit for the next posted zone before entering it.

    • Yes, speed zones denote the borders of zones. In some areas there are now “60 ahead” signs, which allows for a buffer before you get to the actual 60 zone sign.

    • The speed limit is the upper limit, not the prescribed travelling speed. This is why, even though it feels illogical, that you must decelerate before you enter a lower speed zone, and cannot legally accelerate until you reach the higher speed zone.

      You must’ve gotten one grumpy policeman that day.

    • Check your local laws but I had a look into this in Tas and found something to the effect of “There can’t be a speed camera within 200m of a speed decrease”. Now I’m not sure if that means the physical camera can’t be in that space or they can’t ‘get’ you in that space.

      • Yep, they cannot be deployed within 200m of a speed decrease, and must be deployed at least 200m after a speed increase – the current operating conditions and site criteria are publicly available from here:

        The idea being that by setting exclusion zones, the camera/sensor is unlikely to trigger before the new speed zone has been entered – so if you are slowing down before the transition point of 100kph to 80kph like a sensible and conscientious driver, you won’t have an oh-F4 moment when you sight the camera/officer on traffic duty.

        Interesting to note too that Tassie buffer zones rarely exceed 400m, so the camera/officer can typically only be in the 100 zone preceding the downgraded limit, or in the following 60kph zone without breaching speed detection operating conditions.

        • Can you explain that last paragraph again? I can’t quite get my head around it.

      • This may be worth looking into however is wasn’t a decrease sign, it was a speed increase sign (according to the OP)

        • This only applies to speed decreases. This is what the top comment of this thread was asking about.

  • Moby, as another Peth driver I would like to empathize with your comments about wanting to speed up to fit in with freeway traffic. Some cars (/drivers) just can’t get up to speed fast enough not to be a hazard when merging.

    Regarding the camping cops to catch drivers accelerating early, lets not go with ridiculous but perhaps more aptly opportunistic.

  • Yes it is, you can’t exceed the limit but you can go under.

    Going from 80 to 60: you should decrease to 60 before you hit the sign.
    Going from 60 to 80: you should increase to 80 after you hit the sign.

  • The only inconsistency with the laws is that it’s also illegal in WA to do less than 20km/h below the posted speed limit on the freeway, so in some cases where the speed limit increases dramatically from 60km/h to 100km/h, it’s almost impossible not to break a law. However, from memory, the Road Traffic Code (2000) says that, if contradictory laws apply, you must still drive at the slower speed limit.

    Also, your photo shows that you started accelerating well before the change from an 80km/h zone to a 100km/h zone – if your car takes that long to get to 100 from 80 then you have a bigger problem!

    • Was going to say this as well. You can’t even see the sign in the given photo: the 100 zone is well past the merge point. You got done good and proper!

    • The law also makes an exception for travelling 20km/h under the limit if the traffic conditions prevent it, which is absolutely the case when you go from 60 to 100.

  • The fact it’s an illogical law that most motorists break is unfortunately irrelevant. Rules are rules.

    I can’t agree with you that it’s an illogical law – what about if a speed sign on a long stretch of straight road was visible several kilometres in advance? Would it be acceptable to speed up then? What if multiple successive speed signs are visible – which one would it be acceptable to start speeding up for?

    • Yet you’re meant to slow down as soon as a sign is visible, correct? You shouldn’t be exceeding the new speed limit once you pass the sign if it’s a decrease.

      • You’re right that you shouldn’t be exceeding the new limit once you reach the sign, however you’re under no obligation to start slowing down when the sign becomes visible. You just need to make sure that you’re not exceeding the speed limit when you reach the sign.

        When you actually start slowing down will depend on a lot of factors – visibility due to weather, visibility due to other conditions, traffic, type of vehicle, current speed etc.

      • You can slow down any time prior to passing the speed limit sign, it doesn’t have to be as soon as it’s visible. But yes, you can’t exceed zone speed limits, so that means entering new zones at or below the posted limit.

  • Problem for you is that there is an off ramp, and the police convienently chose this as the spot to check this even thought the majority of people caught would be traveling on the freeway. You could argue the speed signs have been poorly chosen and there should really be 80km exit warning signs rather than restricting the freeway speed.

    • The freeway is restricted to 80km/h there because of its proximity to the CBD – nothing to do with the off-ramp.

  • The other side of this is getting rid of human driven cars – the problem goes away.

  • Unfortunately these days its more about revenue raising then road safety. I got booked 20km over because the council had moved a popular bus stop to right in front of the sign so if a bus was stopped you couldn’t see the drop from 80 to 60. As soon as this happened the police were there at random time through out the day catching people doing 20km over and handing out $400 fines. I took it to court and won as neither of us could prove that a bus was obscuring the sign. Within 2 weeks the sign was moved and the speed painted on the road and I have never seen the police there again.

  • This has to be a late April Fools joke or contrived letter to make a point. Nobody can seriously be that stupid and still manage to operate something as complicated as motor vehicle.

  • Technically, OP could argue that he entered the freeway, and there was no speed limit sign. The law states that if there is no sign, the default applies. Since it’s a freeway, the default speed of 100kmph applies.

    I’m also trying to find information on ‘within what range of speed sign can camera be used’ but it’s proving difficult. LH, help?

    • In WA I always thought the speed limit was pretty consistently posted on the on-ramps as per the first photo?

    • Also I believe WA uses 110 for the default non-built-up limit (unlike 100 in other states), just that the vast majority of the freeway is signed as 100 outside the CBD and Graham Farmer Freeway which is 80.

    • I think you’ll find that there are no laws about “within what range of speed sign can camera be used”. Because cameras are ways of determining whether someone is breaking a law, they are not a part of the law itself.

      In Victoria I know there used to be police policies that said, for example, that they wouldn’t place speed cameras at the bottom of hills, and such forth. But they are policies in relation to the police, they are not the law itself, just ways in which police detect law breaking. (the policy no longer exists, I believe, so don’t start speeding down hills people, ride those brakes).

      I think you’ll also find – at least in Victoria – that within metropolitan regions, the default speed limit is 60 on an arterial road and 50 in a residential road. It’s only outside towns or cities that 100 is the default limit.

  • Last week I was driving through a 40 roadwork zone and after the roadworks ended (back to 80) there was a speed camera setup (about 100m, enough time to get back to the 80 limit) behind the change of speed sign.

  • I once heard an argument that you can’t be inconsistent with where signs apply. A give way sign means that you have to slow down before the sign, so the effect applies before the sign, but a speed limit sign applies after…. therefore there’s a difference in were a road sign applies (before or after), and there needs to be consistency. not that I prescribe to this, but i found the argument interesting.

  • Unless you’re riding a unicycle, I’ve never found an on-ramp in Perth that doesn’t give you ample time to accelerate to 100km/h between the sign and reaching the point of merging.

    • as a unicycle rider, I feel the (obviously unnecessary) need to inform you that most standard unicyclists would have trouble reach 100km/h regardless of the distance given.

      • I just checked this out and you’re 100% right. They really should make it illegal to ride unicycles on the freeway over here.

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