Melbourne has one of the largest and one of the slowest tram networks in the world. The longest single use of time on a journey is dwell time, which is defined as the time it takes for a tram to stop, allow for boarding and alighting passengers and starts moving. Because tram patronage is due to increase in the city, there is a need for punctuality and reliability improvements throughout the network.
Previous research suggested there were three defining factors that affect dwell time: passenger behaviour, ticketing procedures and vehicle design. Despite this, there had been no definitive study linking stop design and dwell time. This is especially important at the moment as the Victorian Government has a large investment program that is converting kerb-side and safety zone stops into platform or ‘super stops’ for DDA compliance. This study compared the three stop types (pictured) with dwell time, with interesting results for planners and urban developers.
The data survey took place at three tram stops over three days with nine data lots in total during the morning peaks from 7–9am and the afternoon peaks from 3–6pm. We reflected previous research by counting the number of doors, tram class, crowding in the tram and number of passengers boarding and alighting.
From this data the variables were assessed to see if they were statistically significant to the study. The number of doors on each tram was the same, so this was deemed statistically irrelevant. A four-step scale of crowding was used and a simple regression analysis proved the crowding on the tram to be statistically irrelevant. Conversely, there was a large difference in dwell time per person for each tram class and this was found to be statistically relevant. As such, only data from B Class trams was analysed.
(Three tram stop designs) Three stop types What was found was the platform stops had the minimum amount of dwell time for any of the stop types, at just 4.31 seconds. Next were safety zone stops with 7.38 seconds and kerb-side stops with 12.7 seconds. However, these results were reversed when we looked at impact per passenger. In a kerb-side stop, each passenger has an impact factor on the length of dwell time of 0.48, 0.92 for safety zone and 1.10 for platform stops.
This means that for large numbers of passengers (ie 30 or more), kerb-side stops perform the best out of the three stops. Platform stops performed remarkably poorly for large passenger volumes. For low passenger volumes (ie 15 or less), platform stops have the least amount of dwell time.
One way to explain these results is to investigate the space at the stop. Within the safety zone stop, with the longest dwell time of the three, there is very little space for waiting passengers to move and allow room for alighting passengers. This causes great delay as passengers move about the stop. Likewise, with the new stops the platform, while wider than a safety zone, is filled with fixed furniture, such as seats, ticket machines and rubbish bins.
These extra items on the platform impede passenger movement while boarding and alighting. This could explain the poor performance in dwell time with high passenger movement numbers. This is further compounded by passengers waiting in these two stop types for trams from other routes, a common occurrence in the CBD with many stops having two–three routes sharing the stop.
Conversely, the kerb-side stop allows for great ease of movement in the whole traffic lane that is devoid of cars. In this instance, boarding passengers can move aside to allow room for alighting passengers. Furthermore, in a kerbside stop, any passengers waiting for other trams stand on the footpath, far away from the boarding and alighting passengers.
This study is early work into the relationship between dwell time and stop design. Further work by Monash University in Melbourne is investigating the relationship between streetcars, stop type and crowding.
This is an excerpt from a Monash University student research paper by Samantha Harrison (nee Gelfand). The paper won the 2012 ITEANZ Student Award for an outstanding piece of coursework by a transport engineering student.