How and when did Sydney Light Rail get faster?

Posted: July 13, 2020 in Transport
Tags: ,

VIDEO: Sydney Metro | Demystified (RMTransit)

Sydney’s L2 light rail line has quietly been sped up since it launched in late 2019, with an end to end trip between Randwick and Circular Quay falling from 51 minutes to 38 minutes. Interestingly, much of the improvement occurred prior to lockdown restrictions, which would be expected to reduce delays on the line; trip durations on the line were timetabled to take 40 minutes as far back as mid March 2020. The improved speed appears to be due to shorter dwell times at stations and better use of traffic light priority, but there remains padding in the timetable that provides some potential for additional speeding up of the new line.

Back in December 2019, this blog timed an end to end trip and found it to take 51 minutes, equal to the timetabled trip duration for the opening weekend. A breakdown of the time for the trip found that the main contributors to long trip durations appeared to be:

  • long dwell times at stations
  • traffic lights at intersections
  • waiting for the track to clear
  • low speed limits, particularly on George St

In that blog post, it was suggested that addressing these issues could result in an estimated time saving of 13 minutes, coincidentally the exact drop in trip time from 51 minutes to 38 minutes. To dive deeper, this blog once again took a trip on L2 from Randwick to Circular Quay at midday on Wednesday 8 July.

The trip was timetabled to depart Randwick at 12:16PM and arrive at Circular Quay at 12:54PM, 38 minutes all up. The final trip duration was 39 minutes 36 seconds. Of that, 26 minutes was spent in motion (65% of the total trip duration, compared to 55% on opening weekend) and 14 minutes stopped (of which 8 minutes were stopped at stations and 6 minutes stopped between stations). Unlike the opening weekend, which saw dwell times of around 40 seconds at each station, the standard dwell time was now around 25 seconds. With 12 intermediate stations, that suggests 5 minutes of planned dwell time. Adding this to the 26 minutes of time in motion gives 31 minutes, which would appear to be the theoretical quickest time if there are no delays. That leaves 7 minutes of planned delays, which can be seen as “padding”.

The actual travel time of just under 40 minutes was not dissimilar to the timetabled travel time of 38 minutes. Indeed, the tram was itself delayed due to a late running tram ahead blocking the track. This would not seem to be a common occurrence, as will be explained later. However, given that it was midday while passenger movements remain suppressed due to the COVID-19 pandemic, it should be expected that travel times should be quite close to the timetable.

Dwell Times

Some dwell times were longer when it appeared that the tram was running ahead of schedule at the Wansey Road Station and Royal Randwick Station; accounting for 1 minute 23 seconds of additional dwell time, beyond the standard 25 seconds. However, some stations saw shorter dwell times, presumably to make up for lost time when the tram was running late; including the Moore Park Station (19 seconds), Surry Hills Station (18 seconds), Chinatown Station (20 seconds), and Town Hall Station (21 seconds), which all up accounted for 22 seconds less dwell time. In addition, while at Wynyard Station the tram waited for the track to clear due to the tram ahead itself still dwelling at the Bridge Street Station; accounting for 1 minute 29 seconds of additional dwell time.

All up, dwell time at stations now accounts for 20% of total trip time, down from 27% on opening weekend. Much of this could likely be attributed to the shorter standard dwell time of 25 seconds, down from 40 seconds, which does appear to have shaved about 3 minutes from the total trip duration.

Traffic Lights

The tram stopped at traffic lights at least 6 times, causing a total delay of 4 minutes 46 seconds. The longest of these were 2 sets of traffic lights on Anzac Parade causing a combined delay of 3 minutes 13 seconds between the Royal Randwick Station and Moore Park Station, particularly the first of these traffic lights which saw 2 trams from the L3 line cross, while also allowing phasing for buses to move from the tram/bus shared road and the busway, causing a delay of 2 minutes 34 seconds. The next most significant red light occurred between Central Station and Haymarket Station, causing a delay of 1 minute 4 seconds.

However, most intersections saw quite good traffic light priority, with the tram not stopping at 7 of the 12 sections between stations. Indeed, it would appear that the tram driver showed little hesitation in calling for a green light when approaching a quiet intersection, preferring to run ahead of schedule and spend additional dwell time at stations than to risk running late due to a red traffic light. Though in some cases it also appeared like trams tried to coordinate so that trams in both directions crossed an intersection at the same time, which would have the effect of minimising the impact on cross traffic, or merely waiting when approaching busy intersections where calling for traffic light priority would cause more disruption to road vehicle movements.

All up, waiting at traffic lights now accounts for 12% of the total trip time, down from 14% on opening weekend.

Waiting For Track To Clear

Tram bunching caused a significant amount of delays on this trip. Already mentioned earlier was the additional dwell time at Wynyard Station of 1 minute 29 seconds as well as the traffic light delay from that same L3 tram crossing over from the median of Anzac Parade to the parallel tram road, which caused about half of the 3 minute 13 second red traffic light delay. This L3 tram then caused further delays when approaching the Circular Quay Station of 1 minute 21 seconds. All of these delays are due to tram bunching, and likely added a combined 4 to 5 minutes of travel time on this trip.

All up, waiting for track to clear now accounts for 11% of the total trip time, up from 10% on opening weekend.

Analysis

The reduced dwell times and more assertive calling of traffic light priority are welcome changes, and both appear to have contributed to the shorter journey times. Indeed, it would appear that calling for traffic light priority at quiet intersections is an effective yet pragmatic use of traffic light priority that minimises impact on road vehicles while maximising on time running for trams. In addition, private cars and pedestrians appear to be getting used to trams and do not block their paths as much as they used to.

What remains disappointing is the delays caused by waiting for track to clear. Without these, the trip could have been completed in as little as 35 minutes. However, this may have been the exception, given that tram frequencies along George Street that day showed most trams running 3 to 4 minutes apart. This is close enough to provide a good high frequency service that allows passengers to turn up and go. Even after diverging, a tram every 7 to 8 minutes on the L2 and L3 branches is a decent frequency for those corridors. Importantly, however, the 3 to 4 minute frequency at the core gives trams enough space to not bunch up. After all, the conga line of buses on George Street that brought that public transport corridor to a snails pace was one of the reasons for replacing it with a high capacity rail based transport solution.

But tram bunching does present a serious limit on line capacity. In particular certain choke points remain in places like Anzac Parade where L2 and L3 branch off, the intersection between Rawson Place and George Street near the Haymarket Station, and the intersection between Alfred Street and George Street near the Circular Quay Station. These are all difficult to address, as they already involve complex traffic light phasing that mixes trams with thing like private cars, buses converging/diverging with their own busway, pedestrian crossings, etc. Retrofitting a solution would likely require a shut down of parts of the line for significant periods of time to rebuild these pinch points.

Despite this, it should be investigated. One possible improvement would be to make George Street one way Northbound between Essex Street and Argyle Street, near the Circular Quay Station, thus allowing trams to move between George Street and Alfred Street without needing to stop at the intersection’s traffic lights. Delays here are often compounded by trams having to change track at the terminus, which adds additional conflicts to movements on the line.

Removal of some padding on the timetable could also be investigated. Even without an increase to speed limits, a tram should be able to complete its journey in 31 minutes. So cutting the timetable from 38 minutes down to around 35, maintaining some padding, could be an option. After all, this is a line with its own exclusive right of way, and so should be seen to be a rapid transport service.

Comments
  1. Brian Blunt says:

    “Adhering to the timetable” seems to be a fallacy. Although there is a published timetable available online and in apps, the trams rarely actually run to it (even when “on time”). With a lack of real time data available to the apps, the only way to know when the next tram is due at a stop is to go to the stop and check the display. As this is “real time”, it does continually update and trams can suddenly be due 10 minutes later than they were a few seconds ago. It has not been uncommon to find, say, two L3 trams 4 minutes apart, then a 20 minutes wait for the next one. I regularly go to Chalmers St at around 0700 of a weekday, and often see 3 trams follow each other through the stop.

  2. Tony Prescott says:

    38-39 minutes is the contract time. All they’ve done is brought it down to the contract time. Yes it could certainly be improved and should take no longer than 30 minutes but they won’t because that’s all that they’re required to achieve under the operating contract. All those mysterious slow-downs along the line are merely controls on not getting ahead of timetable. The timetable is now as per contract and the contract is in effect until 2036. It’s a royal stuff-up by TfNSW and Transdev between them and nothing can be done about it now.

  3. Matt says:

    Great article!
    The original business case did say 34 mins from Randwick to circular quay so it is better, but more work required.
    The signal phasing or priority is still terrible, I’ve seen bus or car greens with tram stopped, this needs to be improved.

  4. Stan says:

    Good job and methodology to estimate relability of new transport system. Greetings from high-density tram network in Europe.

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