Wednesday, April 20, 2011

Why LRT? Part 2 - Why Rapid Transit at all?

(Part 1)

This is the second of a multi-part overview on LRT in Waterloo. Like any complex topic, it takes some time to get through, so I'll spread it across multiple posts and link them together. I hope you'll bear with me, and if you have questions, comments or criticisms, please comment below.

There's not much point in discussing LRT without discussing Rapid Transit first. What is Rapid Transit and why is it being considered over conventional route expansion in Waterloo?

Most dictionary definitions of Rapid Transit sound something like "a form of high-speed urban passenger transportation such as a subway or elevated railroad system". The key aspects of a rapid transit system are that they provide frequent, reliable service on a dedicated right of way. Other important aspects are that they provide a convenience and comfort level to attract more riders than conventional bus.

Why Rapid Transit?

Rapid Transit is seen as a way to meet the goals I discussed in the previous post. Properly implemented, an RT system will both drive development around it (attracting more of our growth into the core and reducing sprawl pressure), and improve transit ridership.

Currently RT will only serve the central corridor, but it will connect the densest parts of our region and, in coordination with improved express bus routes and a realigned bus network, provide a more attractive and more useful transit network to a larger proportion of our population.

Why a Dedicated Right of Way?

The most visible impact of Rapid Transit is the dedicated right of way: both LRT and BRT proposals specify it.

The need for the Right of Way is simple: Rapid Transit isn't rapid if it has to compete with regular traffic. The current iXpress is not "Rapid Transit" because of this aspect: its schedule is affected by traffic on its route.

One of the major factors for why iXpress is not regarded as a long term solution is its mixed-traffic status. As our population increases and traffic congestion worsens, so too does iXpress's end to end time. While iXpress, LRT and BRT all project similar end-to-end trip times (around 1 hour 15 minutes), iXpress is expected to worsen to around 2 hours from Ainslie to Conestoga.

Providing a new Rapid Transit system with its own right of way is a large part of the system's expense, but also its saving grace. RT becomes independent of traffic levels. In combination with its own Right of Way, both LRT and BRT would come with signal priority to minimize time at traffic intersections. (Although, how effective this is for BRT becomes an issue-- I will discuss this later.)

It's not all end-to-end trip time, either. Another important factor is reliability. With its own ROW, RT can adhere to its schedule better. Reliability and frequency is a major issue for transit users, and buses in mixed traffic tend to interfere with each other and "bunch up" around stops and traffic lights, throwing schedules into havoc. While iXpress attempts to pass regular route buses when it can, it is still affected by the large number of buses currently servicing the Central Corridor.

Why convert a lane of car traffic into a Transitway?

A contentious issue about the RT proposals in Waterloo is that for much of the route, a dedicated railway or laneway will cost a lane's worth of traffic, as well as constrict several intersections. If the number of drivers are increasing, this seems like a good way to further congest traffic!

And while it does affect traffic capacity along its road-based corridor, the deciding factor is how that lane serves the most people. According to Wikipedia:

  • "Traffic jam" levels of road traffic are at 2000 vehicles per hour per lane (at 1.2 occupants per car, this means ~2400 people per hour per lane)
  • Buses on dedicated lanes (BRT) have a capacity of 7000 passengers per hour per lane (almost 3x)
  • Multi-car LRTs have a theoretical capacity of 20000 passengers per hour per lane. More practically, a system like Waterloo envisions (with a 450 passenger vehicle capacity) would have a capacity around 12000 passengers per hour per lane (5 times!)
In other words, the two lanes of car traffic capacity we spend buy us the equivalent of ten lanes (or 2.5 King St's) worth of transit capacity. And the more who take transit, the more the remaining drivers benefit.

So, to summarize, Rapid Transit:
  • attracts greater ridership and intensification than conventional transit,
  • uses a dedicated laneway that trades a small amount of car capacity for a much larger transit capacity,
  • is capable of more frequent, fast and reliable service than conventional transit along its corridor.

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