Myth: The purpose of tram priority is to stop trams running late
Fact: Tram priority can and should be used to increase the speed of trams (and buses), thus providing both reduced travel times and increased frequency with the same number of vehicles and drivers.

One of the more common complaints about trams is that they are slow. Trams are held up by queueing cars, turning cars and cars that unlawfully double-park or block intersections, and are disrupted by traffic lights operating on cycles that favour cars. Until recently, little attempt was made to help trams get through intersections more quickly, mainly because the motoring lobby opposed—and still opposes, to some extent—any measures that might speed up trams at the expense of cars.

Starting in the 1990s, traffic engineers consented to the insertion of tram-only phases in traffic light sequences: the little white ‘T’ lights that come on for a few seconds at a time. Unfortunately, while in some places this tram-only phase has improved things, in other places it’s just made things worse—because the tram is often prevented from moving except when it gets its special signal. Thus in many locations, tram-only phases are used deliberately to allow cars in lanes adjacent to the tram to proceed before the tram—the opposite of proper tram priority. At the corner of Lygon and Elgin Streets in Carlton, for example, trams are permitted to turn the corner only after cars going in the same direction are given their full green phase to turn left or right or proceed straight ahead.

The upshot is that even today, tram travellers in Melbourne face delays greater than those faced by peak-hour motorists, even when the time to stop for passengers isn’t counted. When VicRoads reported that motorists are delayed in peak hour by an average 49 seconds per kilometre, this was widely reported as ‘unacceptable’ by shocked media. Yet research evidence indicates that trams are delayed on average by over two minutes per kilometre in central Melbourne, and by over one minute per kilometre in the suburbs, due to factors other than passenger boarding—mainly traffic lights.

In other cities that have trams, the trams are given some measure of priority over cars, for example by interrupting traffic light sequences to allow trams straight through intersections, and by measures that discourage long queues of traffic from forming on narrow streets that carry trams. After all, it takes only five seconds to move a tram carrying 100 people through an intersection, even if it takes a full minute and a half to get the same number of people through in cars. So when the former ‘Think Tram’ priority programme commenced in Melbourne in 2004, there was some hope that we may at last see Melbourne begin to catch up with cities like Zurich, Toronto or San Francisco.

Unfortunately there remained—and still remain many years later—some very wrong ideas circulating about the purpose of and supposed impediments to tram priority, which meant even the generous Think Tram funding was not spent in a way helpful to the movement of people in Melbourne. Other pages debunk some of these common notions, in particular that speeding up trams requires tram stops to be moved, or even eliminated.

There is also a view within the planning bureaucracy that tram priority is simply a remedial measure, to be employed when trams are running late and need help to catch up to the timetable. Thus, newspapers report traffic engineers as saying that when installing special priority signals for trams, special attention must be given to ensuring that they don’t trigger in the (unlikely) event that the tram is running early. It’s as though these engineers think the biggest problem with tram operations is that trams are running too fast!

The same thinking is being applied to bus priority. The 2004 upgrade to the Warrigal Road bus route included technology to insert a special phase into traffic signals to allow buses through quickly, rather like the hit-and-miss approach for trams. However, on Warrigal Road the special phase is not automatically triggered by a transponder, as is the case elsewhere. Instead, a bus that is running late (and only when running late) sends a signal to Vicroads’ central controller, and this triggers the signals. Similar bus priority measures implemented in Sydney (which uses the same system to control its traffic lights) only operate when buses are running more than two minutes late.

The sluggishness of Melbourne’s trams and buses is built into current timetables, which include plenty of slack (typically one-third of the running time) to allow for delays due to red lights and traffic queues. From time to time even the slack allowed in the timetable isn’t enough, and trams or buses run late. If priority measures are introduced only to deal with the most serious delays and maintain the current timetables more reliably, that would only improve services to the lacklustre standard they were at in the 1980s. Our tram services would still be among the slowest in the Western world; our buses would continue to be a third-rate alternative to car travel.

Yet this remains the thinking well into the 21st century, if recent Vicroads reports on tram priority experiments are any indication:

It is expected that tram travel time on [Princes Highway East] did not improve due to trams adhering to the timetable. The conclusion is that public transport priority should only be provided when a tram or bus is behind schedule, unless the operation is free running.

—“Public Transport Priority in Melbourne, Australia”, report by VicRoads Signal Services to JCT Traffic Signals Symposium, 2018

If tram priority can be used to allow a tram to catch up a few minutes along its route if it is running late, why not use it more effectively to make an on-time tram a few minutes faster? This is what effective tram priority means: once priority measures allow trams to travel faster, the timetables themselves can be speeded up without sacrificing reliability. Once trams are timetabled to run faster, more people would be encouraged to use them, reducing traffic that once held them up, leading to even more gains. The improved running times can also be used to improve frequency: for example, saving 10 minutes in every hour of travel time allows an increase in frequency from 12 to 10 minutes without any more rolling stock or drivers. This would improve patronage even further.

Effective tram priority is called on to do its job all the time, not just in emergencies when trams run especially late. A faster timetable means a faster and more frequent service can be provided with the same numbers of vehicles and drivers. It can even run on time, as Zurich’s system does.

Last modified: 16 January 2022