Melbourne trams and traffic lights
  Andrew C

Most streets in Melbourne where cars mix with trams have turn arrows at intersections. There is an advance detector loop perhaps 100 metres before the intersection and another at the position where the tram should stop. There is a transponder at each end of the tram, activated at the driving end. The traffic light transponders, not to be confused with the points transponders, are well maintained now, but this was not always the case and many trams had non working transponders, some even missing entirely.

Once the traffic light receives a the signal from the tram, the system should give the tram priority. At times, it happens. Some traffic lights quickly respond to the tram signal, but most do not and if the timing is wrong, the tram will not get priority until the next set of signals. The right turn arrow will come up and clear right turning cars from the tram track. If there is a tram approaching from the opposite direction, it seems to be down to the programming of the individual traffic lights as to which tram gets the car clearing arrow. Some traffic lights will only give one green arrow and then revert to normal operation, while some will give a green arrow each set of traffic lights until the tram has passed the second road loop at the stop.

When transponders were fitted to trams in the late 1980s, we were told that the traffic lights, having received the signal from the tram, would stay green longer and the red signal for the opposing road would be shorter, meaning the tram would be on its way more quickly. While this very obviously happens at one location, city bound trams in Wattletree Road at Dandenong Road, I can’t notice that it happens elsewhere.

Where trams in their own reservation are separated from cars and cars need to turn across the tram tracks, again there are arrows and normally there will be quick ‘T’ light at each cycle of the lights, that is, in one full cycle, turn arrow, straight ahead (a longer arrow with the traffic flow), cross traffic, turn arrow.

A more recent innovation are trailing T lights. The tram brings up the right turn arrow in advance, the cars clear, the tram stops at the stop line, unloads and loads passengers, the lights change to red before the tram can depart, but up comes a ‘T’ light and the tram can depart.

Even more recent are ‘head off’ T lights, which buses have had an equivalent for a long time. I am only familiar with a few tram routes, but for Camberwell bound trams at Punt Road, the tram gets a T light and gets out in front of the traffic, where the road narrows from three lanes, a tram lane and two car lanes to two lanes in the evening peak, or one lane normally because of parked cars.

Again on the Camberwell route, the outbound tram at Camberwell Junction gets a quick T light to get it out in front of traffic, before the traffic gets across the congested road and block the tram from getting across.

As you can see, Melbourne does have priority for trams at traffic lights, but it is very inconsistent. The tram priority system is poorly maintained. A fault or failure can remain for years and I could list innumerable examples. Tram priority lights have been installed in Commercial/Malvern Roads at the corner of Chapel Street, and at the corner of Punt and Toorak Roads but never wired up or activated, that is, they don’t work and never have.

The ability and knowledge is there. The funding and or will is not.

Ah, Dudley asked about pedestrian crossings. There is something that looks like a pointing camera, but is not, on each side of the crossing. I assume it is a movement detector and it is not particularly to do with trams. If the crossing is quickly cleared, the system will turn the lights green for the traffic earlier than is usual.

I haven’t re-read this for clarity or errors, but I hope it makes things a bit clearer.

Andrew C.