Traffic light programming, and the tale of the Magic Laptop

The Magic Laptop

One evening many years ago some PTUA bods and I were meeting with a Vicroads bloke about traffic light priority and other related issues.

He had a laptop with him, and it displayed a diagram of a major intersection; I think it was somewhere out on Burwood Highway.

While pondering topics such as tram priority, he talked us through how the traffic light sequences worked, and how the traffic flows, showing us on the laptop.

And he showed us what would happen if the sequence was tweaked; part of the sequence runs for longer, causing some vehicles to pass through more quickly, some to be delayed a few seconds. Really interesting.

Someone asked: “So that’s a simulation?”

The response: “No, that’s real. It’s happening right now.”

So he’d been fiddling with the traffic lights in realtime, and local motorists were probably wondering why they were zipping through or being slightly delayed.

That wasn’t just a laptop, that was a Magic Laptop.

Spencer Street and Collins Street intersection

Programming traffic lights

Anyway, via this and other discussions with people who seem to know what they’re talking about, I get the sense that Melbourne’s traffic lights are reasonably flexible in terms of their configuration, and can be controlled remotely.

But there’s a limit. They can’t handle all scenarios automatically, so for instance when trials of absolute tram priority were done in Nicholson Street, it needed someone to manually control the lights to give a green for the tram.

There are also apparently limited resources, so opportunities to re-program traffic lights don’t come up as often as they’d like.

Why is it so?

Everywhere in government (as well as in the corporate world), if you go digging, you’ll find there’s usually a reason for something.

Sometimes it’s a reason which doesn’t quite make sense, or is outdated in the face of changing circumstances, but a reason nonetheless.

A couple of weeks ago I noticed that the traffic lights at Spencer and Little Collins Streets had an extraordinarily short green man, only about 18 seconds. Then the red man would flash for about another 10 seconds, and then there’d be a solid red man for a full 40 seconds before the parallel traffic light turned yellow.

This is utterly ridiculous in the central city, next to a major railway station, where pedestrians should be the priority.

Setting it like this is just goading people to cross against the lights.

I made enquiries with City of Melbourne, and discovered it is a road managed by Vicroads. So I approached them about it, and eventually I got a response.

Why was it like this? Because Spencer Street is closed for sewer works south of Collins, and they wanted to allow vehicles to detour into Little Collins easily.

But — as shown by the video — there wasn’t much traffic coming down Spencer that actually needs to detour.

Once they realised this, they set it back. Just like that. Someone probably clicked some buttons on a Magic Laptop, and it was done.

A good outcome, with some delicious technical tidbits in the email trail which I won’t publish, other than to say yes, they really do use the reference numbers on traffic control boxes.

(The few cars, and the number of people crossing Spencer Street against the lights would appear to indicate more needs to be done at this intersection to accommodate pedestrians. Note also that this is just metres from where the old pedestrian subway under the road from the station used to emerge.)

The bigger picture

I’ve also had a discussion about that super-annoying crossing at Centre Road/Eskay Road in South Oakleigh. I haven’t seen it yet, but apparently it’s been tweaked too.

But the bigger picture issue is that traffic lights (even in the CBD) are being programmed with poor outcomes for pedestrians. Sometimes as above there’s a reason — sometimes, apparently, it’s just an error.

Much the same issue occurred at Elizabeth/Little Collins a couple of years ago.

And more recently, City of Melbourne has put in brand new installations that failed to auto activate the green man, despite it being policy within the Hoddle Grid.

(And after they fixed that one, the timing was wrong, with — again — too little green man time.)

These things do make a difference. It’s not just about compliance and safety. The travel mode you want to thrive is the one you should encourage. Make it easier for people to walk, and more people will walk.

What I have learned is that Vicroads is now consulting on some of these issues with groups such as Victoria Walks. This is definitely progress.

Be polite, but firm

Individuals shouldn’t really have to get these things fixed. But in the real world, everybody (including Vicroads and City of Melbourne) is stretched for time, and clearly some things simply aren’t being spotted and fixed otherwise.

So…

Put in a report. Twitter may not be sufficient, so do it via their feedback web site. Include a photo if it’s at all useful.

Be polite. Scrupulously polite. You won’t get anywhere by shouting.

Explain your case. Present the evidence, the logic.

Keep a copy of your query text, and the reference number, because some web sites (such as Vicroads) don’t email you a copy back, and it may be useful at the next step.

If you get a pro forma reply which doesn’t make sense or doesn’t address the issue, query it. Be polite, but firm.

And with a bit of luck, and if your point is convincing, you might just get it fixed.

Of course, what I really want is a Magic Laptop.

Traffic light programming is why your CBD tram trip is start, stop, start

It’s not uncommon to see trams stopped at traffic lights along Bourke Street, sometimes in queues, at locations where there is no stop.

If you’ve wondered why your tram journey is start-stop, it won’t surprise you to learn that the lights are all over the place.

Tram westbound on Bourke Street, waiting at Queen Street

With the handy-dandy stopwatch function on my mobile phone, I timed the lights along the central and western section of Bourke Street.

Bourke 30 / Swanston 30 = 60 second cycle

Bourke 35 / Elizabeth 35 = 70

Bourke 47 / Pedestrian crossing near Hardware Lane 23 = 70

Bourke 40 / Queen 50 = 90

Bourke 30 / William 60 = 90

Bourke 30 / King 70 = 100

No wonder trams have to stop continually at lights!

Trams on Bourke Street

Along Bourke Street, and other CBD tram streets, there are numerous improvements that could be made…

Shorter cycles — There are obviously competing demands on the various streets. Because of large numbers of pedestrians, you can’t necessarily have pre-emptive traffic lights that detect trams coming and switch instantly to give them the green. But you could certainly reduce the cycle times. Judging from existing timings, even with our wide streets, it could be as little as 30 seconds each way, or a cycle every 60 seconds. This would greatly cut down waiting times for trams and walkers and everybody else for that matter — but you’d need to check the 15ish seconds Green Man time is enough to get waiting pedestrians off the kerb.

The King Street intersection is particularly bad, giving most of its time to cars — despite Vicroads data showing traffic on all segments of King Street between Flinders and Latrobe Street dropping between 2001 and 2011, and despite that policy should not be to prioritise cars in and through the CBD.

But William Street is almost as bad, despite having much fewer trams than Bourke Street (typically 5 per hour on route 55 vs about 15 per hour on routes 86 and 96 combined).

To help tram drivers know when to depart, for the spots where traffic lights are distant from the tram stops, they should get these lights working — they’re meant to indicate when the best time is to take off. It doesn’t necessarily result in a quicker trip for the tram, but it may allow the driver to wait for passengers who might otherwise miss the tram, while knowing the tram isn’t about to miss a green light.

That’s the theory, but they never seem to actually operate.

Tram stop, Bourke Street at Spencer Street

Co-ordinated cycles — For where there are multiple intersections which are between tram stops, whether or not they are short cycles or long, they should at least be co-ordinated. In this section the important ones are the intersections at Elizabeth and Queen Streets, as well as the pedestrian light in the middle. A tram leaving the Elizabeth Street stop westbound, and not delayed by anything else, should never get a red light before the next stop — and vice versa.

Obviously you’d need to work out the best cycles for the intersecting streets as well — for trams on Elizabeth Street and buses on Queen Street. But how hard could it be?

With the recent movement of tram stops, there are now similar blocks of traffic lights between stops along Swanston Street and Elizabeth Street.

Traffic light programming isn’t the only cause of tram delays of course.

But if moving people quickly and efficiently around the CBD is a priority — and it should be — these issues need to be addressed.

  • A PTUA study found up to 30% of tram travel time is spent wasted waiting at red lights

You shall not pass

I know it’s been around for a while, but I was quite struck the other day by these traffic lights on the corner of La Trobe and Swanston Streets, facing southbound traffic coming down Swanston.

The left and right arrows are for motor vehicles (which can go left or right, but not straight ahead). The middle two are for cyclists (which have their own “Copenhagen”-style lanes) and trams. They go when all vehicles are stopped (which is also when pedestrians cross La Trobe Street north-to-south).

Traffic lights, corner Latrobe and Swanston Streets, Melbourne

I wonder if these are a little bewildering to novice drivers, having all the lights in a bunch like this? Finding and obeying the individual light(s) that apply to you would be a good challenge for learner drivers (and you’d hope the rest of us can get it).

Any good examples of other complex sets of lights, including in other cities?

Spotted

Spotted around the RACV centre in Bourke Street…

I’m not sure what these things are called. They’re from the days before traffic lights — before my time. The only problem with these ones is that two directions are getting a green signal at once, which would result in a crash.
Traffic, RACV centre

This street sign looks a little different. Ah, you see the footnote on it? “Private lane”. Presumably this is because it leads only to the RACV’s carpark, and is on RACV property. But it may have legal implications as well — at a conventional street corner, traffic coming into the side street needs to give way to pedestrians crossing it, but coming out doesn’t. I reckon if it’s a private lane, then like at a car park entrance, traffic needs to give way in both directions.
Private lane, RACV centre

Spotted

Spotted (by Marita, actually), this amusing van:
If you need a plumber, call A.Carpenter

Meanwhile on the corner of Latrobe and William Streets, they’ve painted arrows and lines to help show drivers where to wait to make their hook turns:
Lines and arrows for hook turns

PS. There are also animated/flashing signs signalling for right-turning drivers to wait. Will see if I can snap a pic of one.

PS. Thursday morning. Here’s a pic showing one of the new flashing “Wait” signs. Similar signs have been installed at the Elizabeth St/Latrobe St corner.

New hook turn signage