Monthly Archives: August 2010

Low impact development near the Navy Yard

Near the soon to be opened and fantastic Park at the Yards, there’s a lot of new low-impact development infrastructure.  These bioretention areas should be a great example of the new kind of both urban and environmentally sustainable infrastructure can be.

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These are not ordinary tree boxes.  Instead of draining into a standard storm sewer, these gutters drain into the tree boxes, where stormwater then naturally drains into the ground instead of into a storm sewer.  This reduces the amount of water entering the combined storm and sanitary sewer, and thus can help reduce the number of combined sewer overflow (CSO) events.  Since the combined sewer system mixes storm water and regular sewage, substantial rainfall will force the system to overflow into area rivers, dumping raw sewage mixed with stormwater directly into the Anacostia and Potomac.

From the street side:

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Storm water will slowly absorb into the ground, aided by the various plants soils that can capture pollutants though the process of biofiltration.  Look at other rain gardens and tree boxes under construction – note the drainage layers of soil and gravel to be added.

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In this completed rain garden/tree box, note the grade of the soil in the box, below the grade of the curb:

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Cross-posted at Greater Greater Washington

Parking, lots and lots of parking!

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There’s been a horde of great parking posts in the last few days:

First, Jarrett Walker documents San Francisco’s new adventure in market pricing for on-street spaces:

The goal is to ensure that there’s always a space available, so that people stop endlessly driving in circles looking for parking.  People will be able to check online to find out the current parking cost in the place they intend to visit.  Parking garages will have a better chance of undercutting on-street rates, so that those garages can fill.  If you’ve ever driven in San Francisco, you know that it’s hard to decide to use a garage because, well, if you just drive around the block once more, you might get lucky.  Under SF Park, if you just drive around the block once more, you’ll probably find a space, but it will cost more than a garage, especially if you’ll be there for a while.  So drivers are more likely to fill up the garages.

Jarrett illuminates some of the problems with truly dynamic pricing – ideally, you’d want to have a price set for a given location and time so that a driver knows what they’ll likely have to pay prior to beginning their trip.  This is similar to all sorts of other goods, where the prices are fixed for consumers, even if the actual prices fluctuate more often.

Jarrett also notes the potential for San Francisco to predict and target prices based on the data these meters will collect.  The city has collected lots of useful parking data, the question is now about using that data and infrastructure effectively.  Walker notes:

In a recent post on congestion, I observed that current road-pricing policy requires us to save money, a renewable resource, by expending time, the least renewable resource of all.  If you’ve ever circled a block looking for parking, while missing or being late for something that’s important to you, you know that the same absurdity is true of our on-street parking policy.  SF Park deserves close watching.  And if it doesn’t work well, ask yourself:  “Is it because it doesn’t make sense to charging for parking based on demand, or is it because they were too timid to do it completely?”  The answer will almost certainly be the latter.   The policy itself relies only on free-market principles that already govern many parts of our economies, because they work.

Indeed, market forces do work.  Similarly, Tyler Cowen raised the subject in this weekend’s New York Times. Cowen focused on all aspects of Donald Shoup’s excellent book The High Cost of Free Parking. In addition to market pricing for parking spaces in order to ensure efficient use, Cowen also addresses parking development requirements:

If developers were allowed to face directly the high land costs of providing so much parking, the number of spaces would be a result of a careful economic calculation rather than a matter of satisfying a legal requirement. Parking would be scarcer, and more likely to have a price — or a higher one than it does now — and people would be more careful about when and where they drove.

The subsidies are largely invisible to drivers who park their cars — and thus free or cheap parking spaces feel like natural outcomes of the market, or perhaps even an entitlement. Yet the law is allocating this land rather than letting market prices adjudicate whether we need more parking, and whether that parking should be free. We end up overusing land for cars — and overusing cars too. You don’t have to hate sprawl, or automobiles, to want to stop subsidizing that way of life.

Market Urbanism chimes in specifically about  minimum parking requirements, taking note of New York City’s efforts to change their laws (including references to Streetsblog’s coverage of the issue earlier this year). Many more also chime in, including Cowen’s personal blog – with posts expounding on his NYT article, Arnold Kling’s response, and Cowen’s response to the response – all worth reading.  As usual, Ryan Avent also responds.

In a similar vein to the parking discussion, Ryan Avent also offered this paper up for review, drawing the conclusion that congestion pricing works best in places that have good transit networks – i.e. where there is an effective alternative to driving.  The abstract notes that the two congestion pricing successes had solid transit systems to rely on.  Ryan notes that congestion pricing can be used for improving transit, but it might be politically necessary to front the costs of those transit improvements prior to implementing the congestion charge.

The limited polling prior to the death of New York’s congestion pricing plan also suggested this – dedication of revenues to transit improvements was crucial for garnering public support.  New York, of course, has the advantage of a transit system as an alternative means of transport.  If a city without such infrastructure were to implement such a plan, might some borrowing against future revenues (similar to Los Angeles’ 30/10 plan) be in order?

Frequency Mapping

Last week, Jarrett Walker had a great post illuminating the basic reasons for ‘frequency mapping,’ where a transit agency maps out transit routes that meet some threshold for frequent service (such as buses every 10 minutes, or 15 minutes, etc).

There are many degrees of frequency and span, but in general, most transit agencies’ service can be sorted into three categories of usefulness based on these variables:

  • The Frequent Network runs often enough that you don’t have to plan your trip around a timetable.  That typically means every 15 minutes or better all day, but it needs to be more frequent than that where aiming to serve relatively short trips — as in the case of downtown shuttles for example.  If you aren’t willing to plan your life around a bus schedule, you are interested only in the Frequent Network.
  • Infrequent All-day services are the rest of the service that runs all day.  This network often relies on timed connections.
  • Peak-only service exists only during the peak period.  It mostly takes the form of long commuter-express routes that add lots of complexity to a system map but represent very specialized services for limited markets.

These three categories are useful in such completely different ways that I would argue they are at least as fundamental as the three basic categories of urban road — freeway, arterial, and local — that virtually all street maps clearly distinguish.

We have some great examples of this in DC.  The entirety of the Circulator network is, in essence, a Frequent Network.  The Circulator aims for 10 minute headways, the routes are fairly simple and easy to understand, and thus people can look at the map and understand where the bus is and where it’s going.

WMATA’s bus map for DC, however, doesn’t make this distinction.  While there is a extra color designation for Metro Extra service (meeting the Frequent Network threshold), the other color distinctions merely show which jurisdiction the bus route operates in.

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The distinction between which services operate only in DC (in red) and those which cross into Maryland (green) isn’t really important for a rider.  Furthermore, the overwhelming use of red for the DC routes makes it hard to follow those routes across the map, seeing where they turn and what streets they travel down.

DC Bus Map WMATA legend

Blue services with dashed lines, however, is indicative of MetroExtra (for some reason, a separate brand from Metro Express), and at least makes a effort at differentiation based on frequency – but that tends to get lost in the visual complexity of the overall map.

There’s a common phenomenon of ‘rail bias,’ (hat tip to The Overhead Wire) where riders will opt for riding a train rather than a bus.  However, rail systems tend to have several key attributes that make them more attractive – the investment in the infrastructure both enables and requires a high frequency of service, and the route structure is almost always simple enough to convey in an easily-understood diagram or map.

The lesson from Jarrett’s post is that simple mapping based on frequency can help address some of the perceived shortcomings of buses.  Even without addressing route structure, this is a relatively simple improvement in communication that helps riders a great deal.

Observations from San Francisco

As a nice respite to DC’s heat, I was able to spend the last week in California – including several days in San Francisco.  Some thoughts and observations from the trip:

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Hills and Grids: Gridded streets have plenty of benefits, to be sure – but the downside is that they do not react to topography.  San Francisco provides the extreme example.  The city has even preserved the right of way where topography makes streets impossible.  My own adventure to the top of Telegraph Hill included ascending the Greenwich Street stairs.

Surely, relaxing the grid would offer opportunities for a more understanding development pattern.  Nevertheless, the spaces along the staircases are certainly interesting, as are some of the extremely steep streets.  Such a pattern would not work in a colder climate that has to deal with ice and snow on a regular basis, however – lest you end up like these poor folks in Portland.

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Trucks and Buses not advised.  Um, yeah.

Trolleybuses: As a direct response to the city’s grade issues, the electric-powered trolley buses are a great solution.  The overhead wires for the buses can be a little obtrusive – but they are not nearly as much of a visual blight as the broader patchwork of utility wires strung from house to house and pole to pole.

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Zero emissions, but the wires (like rails) do act as a visual cue for a newcomer to the city (like myself) to find a bus line when I need one.  That’s a plus.

Signage: Actual signs telling you where you are or what transit line to take, however, are sorely lacking – particularly for Muni and BART.

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We can do better than this – the BART platform at Montgomery station.  The boarding signs for various train lengths is nice, but not all that intuitive – but actually determining which station you’re at when the train arrives is another challenge entirely.  Similarly, on the Muni lines that turn into streetcar routes in the outer neighborhoods, signage at the larger stations is almost non-existent – certainly not useful for a first time rider.

That said – Muni’s route symbology is incredibly easy to understand.  Each line is assigned a name (corresponding to the main street it travels on), a letter (as a single symbol) and a color.  It’s something I think Metro could learn from as its route structure becomes more and more complex.

Wayfinding signage around town, however, was much better.  Kiosks offered maps, highlighted transit routes, and in general provided very useful information – even potential ferry routes, for example:

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My favorite ‘signs’, however, where the ones doing double duty – the public toilets:

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Granted, the actual map here is faded and hard to read, but the presence of a self-cleaning public toilet in a popular tourist area like this is priceless.  Thanks to nature’s urges, I never had a chance to actually use one – but the process seems quite self-explanatory.  If not, there are simple instructions:

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This particular toilet is from JCDecaux, the same outdoor advertising firm that operates Paris’ Velib bikesharing system.

Streetcars: The F Market line’s heritage streetcars are both interesting to see on the street and also an effective part of the transit network.  They’re also quite popular:

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One note about these old PCC cars – when you’re standing (as I was while taking this picture), it’s extremely difficult to see out the small windows of these old rail cars to determine where you are – especially with Muni’s aforementioned lack of quickly visible signage.  The PCC car wiki page talks about “standee windows,” but these weren’t of much help to me.

From the outside, the diverse colors of the various liveries from around the world Muni opts to use are fantastic.

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The liveries include this lovely pastel DC Transit paint job.

More (perhaps) to come later.