TfL to test GPS enforced speed limits

[Darren]

Thanks to an eagle eyed reader for the heads-up on this news story which comes courtesy of Gizmodo.

Intelligent Speed Adaptation (ISA) is a project investigating the possibility of limiting the speed of vehicles to the posted speed limit. There are a number of methods being investigated and GPS is being utilised to facilitate the location awareness aspects.

Now Transport for London (TfL) has developed a road map that contains all the posted speed limits in their area and are testing it with GPS systems. Currently it will warn you when you are exceeding a posted speed limit, a useful service and to be welcomed BUT, they are about to test a system that will prevent you from exceeding the speed limit by taking control of the throttle. There are a great many reasons why the loss of control by the driver over speed is a bad thing, big brother or big mother?
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Darren Griffin

[NickG]

This seriously worries me. Radar is bad enough but GPS is nothing like reliable enough to prosecute people for speeding. It can easily be out by a factor of 2 or more. I recorded all my skiing this season using a Qstarz and at two points, my log says I exceeded 90MPH - and that's a 5 second average. Seriously doubtful!

The only way I can see this working is if they average the speed over a very large distance - eg at least a mile and ignore all temporary bursts of speed which can be due to signal reflections and poor GPS coverage in the urban canyon environment.

I would also never get into a car where ANY automated system has ANY control over the throttle! (and yes, I realise the car's computer already controls the throttle on a technical level, but that's hardly the same as having it control it when it thinks you're doing something wrong based on readings from an external unreliable device).

[grd2]

This could be so dangerous!

You would not be able to use a burst of speed to avoid an incident which I would suggest occurs frequently.

How would this be controlled in areas of limited or no GPS? eg Between tall buildings, tunnels, etc. Would the system default to a nannying 20mph?

You would also get the situation where everyone would be driving with their foot flat on the throttle and allowing the speed limit to control the speed. Bad move. Over recent years, I have had a couple of roads near me where the speed limit was reduced from National Limit to 40mph. In both cases, within a day or two there were relatively serious accidents on those roads I guess because they thought the speed limit was safe. I had never been aware of accidents on those roads previously.

Also, with everyone travelling the same speed, especially on motorways, how many drivers would fall asleep?

It wouldn't be so bad if Speed really was the killer the authorities insist it is. The main reason speed is deemed to be the killer is because it is easily measured and therefore speeding motorists can be easily prosecuted as you all know and love.

It's about time someone came up with a sensible method for measuring distance between vehicles. Enforcing a 2 second gap would result in a much better reduction of accidents.

[NickG]

[253]

[philrich1064]

BIG BROTHER is getting in by the backdoor, unfortunately we know he is there and we are letting him in!

[JimmyTheHand]

There was a fair amount of money given to a "university" to build a car not capable of speeding a few years ago by the DoT (or whatever they are called) IIRC – the person in charge justified it by saying vehicles should not allow you to break the law.

Any reasonable engineer will tell you just how simple this would be to achieve, any good one will then go on to talk to you about limitations of such systems and issues about machine - human interaction and the failure to understand it can make the dangers far worse. Needless to say never saw any of this in the interviews/press – just how thrilled they seem to be at modifying a car :s
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J.

[Darren]

[GPS_fan]

Surely, this device is totally dependent upon the speed limits being accurately mapped, something which would possibly appear to be some time off judging by current mapping standards.

...then, there are roadworks and other temporary speed limits - will the device work in real time?
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Andy
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[mcwarre]

They may be able to manage top speed. Lets think about this for a change rather than knee jerk reaction...

Should they fit this (think of the cost) and they limit a car as it exceeds the speed limit of say 20mph. A cyclist is traveling behind at higher than this (rather easy on the flat). The cyclist crashes into the car. Law suit to follow. They will NEVER get a safety certificate for this.

BTW I have a Masters Degree in Safety Critical Systems Engineering and have worked with safety critical systems for over 4 years. Will they get a safety certificate for automatic control of top speed? Not. A. Chance. Ever.

[mikealder]

I built and used such a system on/ in my car a few years back, it worked very well but does take a little getting used to.

GPS speed was used for the vehicle speed, when it wasn't available due to tunnels/ poor reception the rear wheel speed sensor took over which was calibrated from the GPS data at least every 30 seconds which took care of tyre wear and tyre pressure fluctuations including centrefugal forces.

The car is a mobile test hack/ toy to explore technology with and GPS speed related limitter was of interest so this is what I put together:

1/ Three GPS receivers feed a single RS232 to USB converter which fed the computer within the vehicle.

2/ The rear axle differential crown wheel had an inductive sensor to measure rear axle speed - this was a variable frequency signal which was in direct proportion to the vehicle speed, this fed to data to the computer (most cars have such sensors, they are usually employed for the ABS system, in this case on the Volvo it is standard and feeds both the standard Speedo and ABS system)

3/ Throttle cable had an additional position transmitter fitted which was also connected to the computer.

4/ Throttle kick down cable had an additional switch wired to the computer and if/ when activated would automatically disable the speed limiter system (essential for true vehicle control in case you need to use that extra bit of speed to evade a problem).

5/ Throttle actuator and controller fed with a signal from the vehicle PC.

6/ PC and display which ran Windows XP Pro and Labview software to control the entire system running code written by myself. (Note this wasn't necessary for "normal" usage, but I was also messing with the ECU maps at the same time so the displays gave additional information on how poor the fuel economy was depending upon what ECU map I had selected).

7/ Manual speed limit selection was offered by using a separate software routine running on the ipaq-4700 connected for communication to the vehicle PC via WiFi.

8/ Automatic speed limit selection was available once a road was "mapped" - the maps supplied with the main stream navigation units were (and still are to some extent) woefully inadequate to entrust your license with. Extensive data logging over a few months was all that was needed, venturing outside the "covered" area the system automatically dropped back to manual mode.

I built the above as a "little project" to see if it could be made to work, which in the end it did very well. You could full throttle the pedal away from the lights and the car would top out at whatever the speed limit was for the selection made (or auto when data was available). Pressing the throttle further activated the kick down which returned the system instantly to "normal" allowing over speed should it be required.

The strange approach to driving this way though was to depress the throttle and let the vehicles speed be modulated by the speed limit of the road (assuming clear conditions - a bit like an "intelligent" version of the speed limiter option the Merc's have been fitted with for a while).

It took a while getting used to it and the wife refused to drive the car (big plus point) - I had to remove the PC dashboard though when an MOT inspector refused to even test the vehicle with it fitted - his view being that it was illegal - I replaced the instrument pod with standard Volvo instruments and never put the TFT displays back in, the throttle linkage is still "fly by wire" as I couldn't be bothered taking that lot out.

So GPS speed limitting can be done and is very handy in use as a measure to prevent inadvertent speed limit incursions; sadly I don't think this is what the authorities would use such a system for. If they want to start tracking vehicles this way though the real plus point in our favour at the moment is the amount of data such a system creates and the fact a car is not tethered, the UK mobile phone network would instantly fall over if 20M+ vehicles started relaying data back to the authorities at rush hour - Mike

[DennisN]

[superref_63]

An interesting story –

I for one won’t mind my Sat Nav (TomTom 710 about to change to 730) showing me the speed of all the roads in London and it already warns me if I go over the speed limit but is it accurate enough? No!

I checked my speed n the way to work – my speed on the dial said 40 and the Sat Nav said 37 – that is not accurate enough to track people and fine them for “speeding” and also the speeds presently included in the maps are sometimes wrong even on main “A” roads- so we are a long way from seeing this if ever.

Also but not everyone has Sat Nav’s – and they are not standard in new cars

Or is this TFL just scaremongering and trying to look good in front of the new Mayor who apparently doesn’t like TFL!

I can see an increase in WiFi Average speed Cameras (presently on trial at Blackwall Tunnel Northbound) to enforce the local speed limits say around schools

[Anita]

[NickG]

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