Human Transit

canberra: a new circulator network for the national core

Washington DC has its downtown circulator, and now the Washington DC of Australia, Canberra, has one too. What's more, my clients in Canberra created their circulator for almost zero in new operating costs, using one of my favorite planning tricks. Starting next week, four color-coded lines will provide frequent links among all the major tourist attractions, government buildings, universities, commercial districts, and interchange points in the dense core areas of the Australian capital.

For the whole brochure on the circulator, click here: PDF

Where did all this new service come from? Most of it was already there, but was presented as a tangle of several infrequent lines.  These were just too hard to figure out for someone making quick trips around the core.  Short trips are very time-sensitive, and that includes the time it takes to figure them out.  So circulators have to be frequent and simple.

For several years, Canberra has been discussing options for creating a shuttle system to link these core destinations, but they could never find the money.  Instead, I suggested that we look at whether bus service that's already there could be branded to form legible and frequent circulator lines.  It turned out to be possible, with only slight service additions and some careful revision of timetables.

The Gold Line and Green Line are each created out of two existing routes that are every 20-30 minutes when separate but that combine to provide high frequency when running together.  When they're separate, they're just Routes 2, 3, 4, and 5, each doing its own business. But when Route 2 and 3 are together, that common segment is branded as the Gold Line. Likewise, the segment where 4 and 5 are on top of each other will be called the Green Line.

Signage and new marketing will highlight that you can use these colored lines to circulate around the core, and you don't have to care what the line numbers are. People don't have to remember that to get from the City station to the National Library they need the 2 or the 3. Instead, they can just remember the Gold Line.

Obviously, a combined frequency of 15-20 minutes is not enough for a true circulator, and the goal is to get to 10 or better as demand grows.  Now that Canberra has the color-based brands, future planners can easily decide to design other lines to flow through the branded segments, thus contributing to the combined frequency.  In many cities, there are situations where six more more half-hourly lines are effectively right on top of each other for a long distance; those are ideal candidates for a color-based brand that combines them into a (possibly very frequent) shuttle.

At the same time, Canberra is re-branding the two existing Rapid bus corridors as the Blue Rapid and Red Rapid. The Red Rapid happens to be one frequent line with no variants, but the Blue Rapid is formed of many overlaid lines, all numbered in the 300s, that do different things on outer branches but all run along the same Rapid segment linking several major town centers.  Together, the Red and Blue Rapids will form the frequent rapid-transit backbone of Canberra's all-bus network. As it happens, they also link some useful dots within the core area, so they're on the core map as well. 

This branding technique is often useful in relatively small cities that have a few strong frequent corridors.  I first suggested it in Bellingham, Washington, a university town north of Seattle, and this shelter displays one of the results.   Again, the Blue Line consists of a big pile of three-digit route numbers, but now nobody has to remember those numbers to navigate this high-demand corridor that runs through the university and into downtown.

Often in small cities, these frequent segments are served by several different routes overlaid, but the pile of route numbers makes the service seem complex.  The color brands let people ignore that complexity and see the frequency clearly instead.  And since frequency is the foundation of freedom for transit riders, transit agencies that want to be instruments of freedom should make it as visible as possible!

tyson's corner: the "last mile" problem

Tyson's Corner, Virginia west of Washington DC is one of America's classic "Edge City" commercial centers.  It looks like the result of a global design competition based on the question:  "How can we build an urban center of shopping and employment that will attract 100,000 people per day, concentrated in a 5 square mile area, while ensuring that almost all of them come by car?" 

You know the look.  Lots of big office buildings with big parking structures, served by car-oriented arterial streets that are neither safe nor pleasant to walk on, all focused around a freeway interchange.

Rapid transit is finally coming in 2013 via the WMATA Silver Line.  The Silver Line will have four stations in Tyson's Corner, but still many destinations there will be too far to walk.  So Tyson's will be an excellent case study of rapid transit's "last mile problem."  When retrofitting rapid transit into a car-oriented suburban area, access from the station to the activity destination is often the problem that drives potential riders away.

Fortunately, sharp minds at Greater Greater Washington are on the case.  They've done a series of posts looking at the Tyson's problem, including:

• An introduction to the problem.
• A busway solution, in which shuttle buses linking the major buildings would run in exclusive lanes.
• An overview of "Personal Rapid Transit" as it might apply to Tyson's.
• A review of limitations of the "PRT" solution. 

If you haven't encountered "PRT," their last posts, and the abundant links in the posts and comments, will give you everything you need to form your own view.

vienna: life without loops

Vienna offers a really nice example of the perils of short downtown shuttles in general, and loops in particular.

on one-way loops

On Transport has a nice post on the Detroit People Mover, a loop that connects a number of major employment and activity centers in downtown Detroit.  

In a recent post I argued that downtown shuttles aren't of much use unless they're extremely frequent.  The Detroit People Mover doesn't have that problem; it runs every 3-5 minutes.  It has the other common problem of downtown shuttles: it's a big one-way loop.

(Detroit's loop is clockwise, having reversed direction in 2008.  Some one-way loops, like the one at the heart of Melbourne's train system, also reverse direction in the middle of the day.)

the problem with downtown shuttles

A common misconception about downtown areas is that great things can be achieved by "shuttles" or "circulators," short routes that just run around in downtown.  The problem with these lines is that they save time for the customer only if they are very, very frequent.  This is an issue that separates people who need only a symbolic service (such as a line on the map or a photo of the transit vehicle in front of the development they're trying to sell) from people who want actual mobility.

Frequency is really important, but it's also really expensive.  Doubling the frequency of a service (i.e. halving the "headway" or elapsed time between consecutive trips on the line) comes very close to doubling its operating cost.  If you double your peak frequency (i.e. the highest frequency you run) it also doubles your fleet, which doubles your fleet capital cost, your ongoing mainteance cost, and the size that your storage and maintenance facility needs to be.  So it's not surprising that we see a lot of downtown shuttle services that offer a line on a map, and a photographable vehicle, and even some mobility for people who aren't in a hurry, but that don't really compete with walking, at least over part of their length.

For an example, let me pick on a very credible-looking route from a proposed downtown Oakland (California) streetcar network, from the interesting Bay Area blog 21st Century Urban Solutions, by Daniel Jacobson of Stanford.  Daniel has lots of good ideas, and I recommend his blog, so I hope he won't mind me using his idea as an example.

The blue, red, and green lines on this map flow across the downtown and out into surrounding neighborhoods, so they would presumably be useful to people who are travelling 2-3 miles or more.  

But the orange line is just a simple square loop.  (If you know Oakland, the four streets are Broadway, 17th, Madison, and 8th.  That suggests a one-way loop, which is a topic for another time.  For now let's pretend the loop is two-way.)

The long sides of the loop are about 770m and the short sides are about 710m, so the longest distance served by the route (from one corner to the diagonally opposite corner) is only 1.48 km or 0.9 miles.  So if you walk at 3 mph, a walk between opposite corners of the loop would take 0.3 hours or 18 minutes.

If a streetcar or shuttle bus doing the orange line wanted to be faster than walking, how frequent would it have to be?

Let's generously assume our service averages 10 mph.  Well, the travel time onboard to go 0.9 miles at 10 mph is 0.09 hours or 5.4 minutes.  So if you just missed one trip, and the streetcar is still going to be faster than walking, that means the next one needs to come soon enough that your travel time plus wait time doesn't exceed the 18 minutes it would take you to just walk the whole way.  The in-vehicle travel time is 5.4 minutes, so that means the headway (time between consecutive trips on the line) can be no longer than 12.6 minutes (18-5.4).

To get to that, I've assumed that the only market the streetcar is serving is between its opposite corners, the longest possible trip that this route can serve.   But the average trip served by this route is obviously shorter.  If you assume a shorter trip, the frequency needs to be even higher.  Let's say we're just travelling the length of one long side, say from 8th to 17th on Broadway.  Now the walk takes 10 minutes while the ride would take 3 min, so it's faster to walk unless the next vehicle comes in 7 minutes or less!

If every urbanist and architect and downtown booster had been stepped through that calculation, we'd see a lot fewer short downtown shuttle services, and the few we had would be much more frequent.  Such services may be helpful for people who don't want to walk for reasons other than time (such as weather, frailty, disability, or laziness) but they offer very little to the average working person who really needs to get somewhere and whose time is valuable.

Sensitivity to frequency is also the main reason why spines of very frequent bus service, converging from routes all over the city, are better than dedicated shuttles at serving short intra-downtown trips. Downtown boosters want specialized downtown services.  But if you just want to get somewhere fast in a major downtown, head for a street where lots of bus lines are running on top of each other to provide a very high combined frequency; many downtowns have one or two corridors where a bus is coming every minute or two all day.  The key here is that the bus service is there anyway, it's already paid for, and it's extremely frequent. By contrast, a city will need to come up with every dollar to run its specialised shuttle, and is therefore likely to settle for a frequency like 12 min or 15 min.  That sounds good, but it doesn't compete with walking for the short trips that the shuttle claims to serve.