Rayaprolu, H., Wu, H., Lahoorpoor, B., and Levinson, D. (2022) Maximizing Access in Transit Network Design. Journal of Public Transportation. 24 [doi]
This study adopts an Access-Oriented Design (AOD) framework for optimizing transit network design. We present and demonstrate a method to evaluate the best combination of local and express alternative transit system designs through the novel concept of ‘iso-access lines’. Two bus network system designs were explored for a greenfield development in suburban Sydney: through-routed transit lines (T-ways) with higher speeds and more direct service, but longer access and egress times, and local routes that provide additional spatial coverage. We developed scenarios with T-ways only, local routes only, and both, and computed transit access to jobs as a cumulative-opportunities measure for each scenario. Local routes offer greater overall access, while T-ways provide greater access-per-unit-cost. The optimal combination of the two was established by generating ‘iso-access’ lines and determining access-maximizing combinations for a given cost by applying production-theory principles. For 15-min access, the optimal combinations had T-way service frequency equivalent to 0.48 times that of local routes. This ratio increased to 1.45, 2.05 and 2.63 for 30-min, 45- min and 60-min access respectively. In practice, the method can be applied to determine optimal transit combinations for any given budget and desired access level.
This thesis systematically develops a network correlation matrix that explicitly distinguishes competitive and complementary link pairs in transportation networks. Embedding the matrix in network econometric analysis, this thesis consolidates that incorporating representative spatial information with a network perspective is capable of improving the performance of traffic forecasting models. The method is validated in the context of a real-world transport system rather than within simulated settings adopted by previous research. An Autoregressive-Distributed Lag (ARDL) model is specified, and reveals that the combination of correlation strength and magnitude of lagged flow change on correlated links is an significant predictor of future traffic flow. This thesis innovatively extends network econometric methods, previously exclusively used for traffic flow forecasting, to the domain of network structure prediction by specifying a logit model. It finds that complementary and competitive links play distinct roles in shaping the network structure. If positively correlated, a link is more likely to undergo the same structural change influential links underwent previously where the influence is measured by a combination of correlation strength and link importance, reflected by historical flow level. Additionally, this thesis establishes a digitized database of the Sydney tramway system, providing a complete set of data for more research.
Transit accessibility to jobs (the ease of reaching work opportunities with public transport) affects both residential location and commute mode choice, resulting in gradations of residential land use intensity and transit (public transport) patronage. We propose a scaling model explaining much of the variation in transit use (transit commuters per km2) and residential land use intensity with transit accessibility. We find locations with high transit accessibility consistently have more riders and higher residential density; transit systems that provide greater accessibility and with a larger base for patronage have proportionally more ridership increase per unit of accessibility. All 48 metropolitan statistical areas (MSAs) in our sample have a scaling factor less than 1, so a 1% increase in access to jobs produces less than 1% increase in transit riders; the largest cities have higher scaling factors than smaller cities, indicating returns to scale. The models, derived from a new database of transit accessibility measured for every minute of the peak period over 11 million US census-blocks, and estimated for 48 major cities (MSAs) across the United States, find that jobs within 45 minutes most affect transit rider density. The findings support that transit investment should focus on mature, well-developed regions.
Zhuzhou, Hunan, China has deployed a segment of `trackless trams’ (map – it runs on the north-south route in the center of the map in this Olympics district). The technology, explained in this video, is an articulated, rubber-tired on road, electric vehicle that carries passengers on a marked right-of-way adjacent to traffic. The interior has a layout typical of trams or LRT vehicles, and it has tramlike doors. The stops are at stations with protective gates aligned with platform doors like modern LRT and Metro systems so people are less likely to be on the track. The vehicle, though billed as “autonomous” is in fact merely “driver assist”, as the video plainly shows a driver and steering wheel and explains. The markings on the road are used to help the guidance system (and the driver) stay centered in the lane.
There is a lot of hype about such systems. It is being widely promoted by Prof Peter Newman out of Perth (Curtin University), who has long been influential in transport policy in Australia, and has had government positions. (You may remember him from Sustainability and Cities).
In Australia, `trackless trams’ keep getting suggested for various corridors, two in particular are”
From the City of Liverpool (Western Suburb) to the now under construction Western Sydney airport Links: (1) (2) (3) The Liverpool – airport corridor has been mooted for public transport, and BRT seems perfectly logical there, trackless tram loses the ability to feed the line from side streets.
Parramatta Road from the City of Sydney to Parramatta. This is a suburban strip/car sewer for much of its length, and could be so much more. With the construction of the tunneled motorway project (WestConnex), there have been promises made to rejuvenate the road and create an exclusive transit lane for its length (it exists in places but not continuously), but commitments are fluid. The route once had trams, and today has many many buses. Links: (1) (2) (3)
One broader issue of course is that it is a bit of vapourware. There is a Chinese line as noted above (so it is decades ahead of Hyperloop), but essentially no one here has ridden on it, and many people/professionals are naturally skeptical of performance and reliability and real costs.
Politicians however are especially vulnerable to the new and shiny (the TV series Utopia/Dreamland is a documentary), anything that gets them above the fold in the newspaper or on the local news at 6, so it attracts more attention than more mundane ideas like bus electrification and exclusive bus lanes and transit signal pre-emption, in short Rapid Bus or Bus Rapid Transit.
And there is a strong anti-labour thread in these discussions, so any opportunity to automate and get rid of drivers and of the risk of labor work actions is seen as attractive. That said, the technology isn’t actually automated yet. Not to say it won’t be in the indefinite future, but not for the initial deployment.
Trams in Sydney especially are seen as expensive, and the two of the most recent tram projects (Newcastle LRT, and the City and Southeast LRT in Sydney) have had huge cost blowouts (and were poorly scoped), so naturally there is searching for other modes.
Perhaps electric bus rapid transit needs a rebranding, but no one should be confused about what a `trackless tram’ actually is. It is an advanced, electric bus in an exclusive bus lane operating like gold standard bus rapid transit. There is nothing wrong with advanced buses. There is nothing wrong with bus lanes. There is nothing wrong with bus rapid transit. Cities should deploy more of these things, and if politicians need to use the silly phrase “trackless tram” or anything else to get this popularly accepted by a political class, media, and public with the attention of a gnat, there are worse indignities the profession suffers.
Sydney opened the long-awaited first Northwest section of its “Metro” line. Sydney has long had grade-separated, high-frequency train service (Sydney Trains) through its core, the “Metro” is different in that it is:
single-deck rather than double deck, with more doors, for faster boarding times
standing rather than sitting oriented (on a crowded train more standees than seated passengers, compared with Trains)
automated rather than manually driven
with platform-based as well as train-based doors, to improve safety.
In other words, while Sydney Trains is what Americans would think of as commuter rail, but on steroids, Sydney Metro is like late 20th century (early 21st century) trains built in much of the developed world, most similar to systems like BART, DC Metro, or MARTA.
To get to the Metro, we took Sydney Trains from Redfern to Epping. At Epping, one descends and descends to reach the Metro platform. The stations and controls from Epping to Chatswood were remodeled from the early 21st century trains line (when the corridor was expected to be a Trains rather than a Metro. We took the line west to Tallawong (a parking lot and near the train stabling facility), and alighted and boarded the eastbound train which we took to Rouse Hill, where we alighted for lunch, making a series of culinary choice errors at the Rouse Hill food court, though I am not clear one could do otherwise.
The good news is that demand was high (75,000 in five hours, the Sydney Morning Herald gushes), apparently exceeding expectations. People are curious about the line, want to see it succeed, want to be able to use public transport to reach the city. Even before the problems that I will soon describe emerged, it was Standing Room Only on the westbound run.
The trains had indicators showing where they were on the line. There was an emergency stop button located near the doors which look like a User Interface disaster waiting to happen (that is, there will be an enormous number of false positives as people will push the button accidentally or in the believe it is required to open the door, as in an elevator).
The braking sound of the train is very much like DC Metro, though deceleration did not induce the same kind of nausea that DC Metro does. There is nevertheless a significant uncomfortable jerk as the Metro train comes to a stop at many of the stops.
After thoroughly exploring the Rouse Hill Town Centre, we queued up to board the Metro back, to go to Chatswood, and then transfer to a Train back to Redfern.
The bad news is the service operator (MTR) was not quite ready to provide a reliable service. We may eventually discover whether someone(s) specifically screwed up, or whether failure is indeed an orphan. Apparently (I did not witness this, but people report) there were issues with platform and train doors aligning, and issues with doors closing properly and with trains overshooting the platform. This held up trains Chatswood and Macquarie Park, and thus eventually all the trains in the line, as shockwave of stoppage cascades backwards all the way to Tallawong.
It took 1 hour and 40 minutes from Rouse Hill to Chatswood. The first 40 minutes were queueing at Rouse Hill, so as not to overload the platform for the few trains making it through, it was no 90 second, or 4 minute, or 5 minute headway as variously promised by various people at various times. The remaining hour was on train from Rouse Hill to Chatswood. The scheduled time is 35 minutes station-to-station.
This opening debacle will, as first impressions are important, likely create a perception that the service is unreliable. If this is coupled with a few well-publicised rush hour breakdowns, it will take years to fully regain a reputation for reliability, and people will clamor for restoration of more express bus services. Obviously some of this technology problem is teething issues, and will be eventually sorted out, but surely this should have been worked out in testing … unless it was rushed for some reason.
The queue management was professional if indicative of problems. The communications with customers about the problems was vague.
Now, to be fair, opening day often brings about unexpected outcomes.
The opening of the Green Line light rail between Minneapolis and St. Paul was marked by an automobile wrongly driving on, and getting stuck on, tracks; and the train hit multiple pedestrians in its first year.
The Opening of the Liverpool and Manchester railway killed a prominent Member of Parliament. So the delays on the Sydney Metro are perhaps small potatoes in the scheme of things. One just would have hoped for a better performance.
* I am not commenting on the strategic decisions about the location of the line, etc. here.
Once upon a time (1888 to be precise), the United States and the world launched a huge building boom for urban streetcars. Companies like Twin City Rapid Transit laid miles of track in fast-growing cities, extending well past the built areas to serve greenfield sites for emerging suburbs waiting to be platted and built. They did this because the streetcar promoters benefited directly from the land sales. The availability of a new, fast transit system connecting to downtown made houses much more valuable. The fares from the new passengers covered the operating costs of the system.
Train riders have to get to stations somehow. This is often referred to as the “first mile” or “last mile” problem. There are many technical solutions to help travellers get from home to the station and back, ranging from cars to electronic scooters, but most people use a much older technology, their feet, to get from A to B. What is seldom considered is access to the train platform itself.
Stations are not points but places. They occupy a large area. A person walking at average speed takes about two minutes to walk from one end of a full-length eight-car train to the other.
Often platforms have a single access point on one side of the station, which makes it more difficult for people on the other side of the station to get to the platform. Passengers may need to almost circumnavigate the station to get to the platform. At an average walking speed, the extra distance they must backtrack adds up to six minutes per trip each way, our research has found.
Imagine being so unlucky to have an extra 12 minutes of travel time every day if you take the train. You might be tempted to drive instead.
The table below shows the extra travel time in minutes depending on platform locations and access points for a traveller’s origin and destination. The average time for such a one-sided configuration of train stations is 3.25 minutes each way.
Table 1: Additional Travel Time Depending on Origin and Destination Residence and Workplace Location vis-a-vis Platform Location.
While this example is hypothetical, it is drawn from experience in Sydney, where 44 of 178 train stations have only a single side entrance.
So what impact will a second entrance have?
We examined those stations and access to their platforms: how many people lived within 5, 10 and 15 minutes of the station platform, considering actual entrance location, and how many jobs were within 5, 10 and 15 minutes of the platform. Using existing ridership data from Opal cards, we estimated a model that related the passenger entry and exit flows at each station to that station’s accessibility.
We sketched a second entrance at those 44 stations and measured accessibility again. It’s now higher, as having two entrances instead of one means more people can reach the platform in the same time. We then estimated the increase in ridership from the model due to the improved accessibility, assuming no change in population or employment.
Over all 44 stations, total morning peak period entries increased by 5%. But some stations benefit a lot, and others not at all, so prioritisation of investments matters.
It will be no surprise to locals that Erskineville station comes out on top with a nearly 35% increase. While many of the new apartment-dwelling residents west of the station make the extra hike every day, even more would catch the train if there were a convenient entrance.
Other top 10 stations include: Bankstown, Newtown, Villawood, Redfern, Burwood, Sydneham, Caringbah, Meadowbank and Penshurst. Planning is already under way to improve Redfern station.
While this result considers existing development, adding a second entrance can make new transit-oriented development that much more valuable. This is because it will likely increase activity on the previously less accessible side of the station, as the example of Erskineville shows below.
Other considerations include accessibility for people who cannot use staircases, as many of the stations are older and will require lifts. The prospects of park-and-ride lots, the costs of construction, the presence of nearby stations, and site feasibility also play into final decisions.
I am a notedstreetcar skeptic. I have written blog posts about their issues. As an objective analyst, I will however admit an advantage streetcars or trams have over buses.
This is not the ‘permanence’ justification that is often heard and easily disproved (i.e. where are they now if they were so permanent?). But it is related, once laid down, tracks are harder to move than buses, and tracks are more expensive, so it is harder to make routes circuitous. Many bus routes look like they were designed by drunk transit planners. One local bus the 370, which runs near my office and my home is so circuitous it is faster to walk even ignoring schedule delay. (It is not quite faster to walk end-to-end though, walking time is 2:30 vs. 1:14 on the bus, so the effective bus speed, assuming schedule compliance, is about 9.6 km/h vs. 4.8 km/h walking.) I have written about this before in Minneapolis, (and nearby Rosedale) and circuity is hardly an unknown problem.
Now there are undoubtedly reasons for every indirect deviation that diverts buses from the straight and narrow. However, every circuitous zig also loses passengers, and bus routes in the US are much more circuitous than travel by road. Serve this building, serve that one, cover this street, reduce pedestrian walking time.
In contrast, trams in practice are much more straight-laced, paragons of transit routing virtue. The historic Sydney Tram Map, as this map in wikipedia shows, gives a sense of routes that were pretty much as direct as possible.
Now it can be argued this particular bus provides and east-west service that no tram did, which is true in part. But that doesn’t mean trams could not. It also could be argued that almost no one rides the 370 end-to-end. Though I have not checked the Opal data, this is probably true as well. But a well-structured suburb-to-suburb transit network (my fantasy map is here, Jarrett Walker has done this as well) could avoid this. To be fair as well, the Sydney frequent network is not nearly as circuitous as the 370 bus, which has a roughly 20 minute headway
This paper describes the connection between stop spacing and person-weighted accessibility for a transit route. Population distribution is assumed to be uniform along the line, but at each station, demand drops with distance from the station. The study reveals that neither short nor excessive stop spacings are efficient in providing accessibility. For the configuration of each transit route, an optimum stop spacing exists that maximizes accessibility. Parameters including transit vehicle acceleration, deceleration, top speed, dwell time, and pedestrian walking speed affect level of accessibility achiev- able, and differ in their effect on accessibility results. The findings provide an anchor of reference both for the planning of future transit systems, and for transit operators to make operational changes to system design parameters that improve accessibility in a cost-effective manner. The study technically justifies the “rule of thumb” in setting different stop spacings for metro, streetcars, and other different transit services. Different types of transit vary in their ability to provide accessibility, slower moving streetcar (tram) type urban rails are inherently disadvantaged in that respect. Thus the type of transit service to be built should be of particular concern, if the transit is to effectively serve its intended population.