What’s the Ideal Size for a Transit Walkshed?

July 8th, 2014 2 comments

Large transit walksheds are great, but how big is big enough?

In other posts, we have described what a transit walkshed is, and how changes can be made to the pedestrian network to increase the walkshed area.  Here, we explore how big is big enough.

The diagram below shows a half-mile circle around a transit station.  If the station were located in a field of grass or on a massive parking lot, the walkable area of the circle would be the circle itself, 100% of the half-mile buffer around the station would be accessible by foot.  Unfortunately, that wouldn’t bode well for transit use, since there wouldn’t be any origins or destinations within that walking distance.

Ideal Walkshed DiagramNow, let’s lay a perfect grid of streets across that half-mile buffer.  The street area is where people can walk, and the remaining area contains houses, shops, mixed-use development, etc.  The resulting walkshed for the station begins to look like a diamond inscribed inside the circle.   The smaller the blocks (the closer the streets are to one another) the more the walkshed resembles a perfect diamond that has a diagonal distance equal to the diameter of the circle.  If you take the area of the diamond and that of the circle and compare them, you find the walkshed (square) covers 63.7% of the circular station area buffer.

So if you have a perfect grid and get 63.7% coverage, how can you get any better?  For one, diagonal streets can increase the coverage: if two diagonal streets were added to the grid, intersecting in the center of the circle at the transit station, the square walkshed would turn into an eight-pointed star, increasing coverage even more, but not by much.

An good example of a walkshed greater than 63.7% is that of the Takoma station.  Featured in a previous post, we recently calculated a 91% coverage for Takoma.

It is difficult to pick an ideal size for a transit walkshed.    A larger percentage could be beneficial, but the additional roadway network needed to expand the coverage beyond 63.7% may result in less area dedicated to potential transit origins and destinations.  (Remember the station in the parking lot?)

What Metrorail stations do you feel have good walkshed coverage?  In  your opinion, where can we improve?

 

 

We Had Bus Lanes a Half Century Ago and We Can Again

July 7th, 2014 7 comments

Despite having two million fewer people, our region used to have 60 miles of bus lanes.  It’s time to revive them.

Bus Lane on 14th Street in DC

Bus Lane on 14th Street next to the National Mall in the early 1970s

Did We Really Have That Many Bus Lanes?

Yes.  In the 1960s and 70s before Metrorail was built, Washington and its surrounding inner suburbs relied heavily on its bus system to get around, with very frequent service on a number of major streets.  According to our records (linked at the bottom of this post), the first bus-only lane was installed in 1962 on 16th Street NW in DC, generally between H Street NW and Florida Avenue NW [DDOT Fact Sheet, p. 6].  This was followed by dozens of miles of rush-hour and full-time installations, as shown in the map and table below.  Streets in red indicate bus lanes that were implemented as of 1976, while streets in black and blue represent bus lanes that were planned but, to our knowledge, never put in place.

Read more…

New Blue Line Connections Revisited

July 3rd, 2014 23 comments

A recent Metro study determined that a Rosslyn bypass is infeasible but a second Metrorail station in Rosslyn to restore frequent peak period Blue Line service is possible.

In a post last year describing the strategies in Metro 2025, we described some options for new Blue Line connections.  The first was a Rosslyn bypass that would allow some Blue Line trains to connect directly to the Orange Line at Court House.  The second was a second Rosslyn station that would connect to the current Rosslyn station via an underground walkway.  Both of these options, illustrated in the graphics below, would allow increased frequencies on the Blue Line during peak periods.

Graphic for Rosslyn Interline ConnectionGraphic for Second Rosslyn Station

Metro recently completed a study that evaluated these two options.  The bad news is that the Rosslyn bypass (interline connection) was deemed infeasible.  This is due to the location of building foundations and the turning radius required by the track.

However, the second Rosslyn station was deemed feasible, as illustrated in the map below.

second_rosslyn

Location for a proposed second Rosslyn Station, including three potential options for a pedestrian walkway.

This new Metrorail station would connect to the current Rosslyn station via one underground walkway.

Metro Office of Planning is submitting the second Rosslyn station for project development funding.

 

How Can The Coverage of Transit Walk Sheds Be Increased?

July 1st, 2014 2 comments

Pedestrian infrastructure can cost-effectively increase coverage of transit walk sheds.

The roadway networks of most station areas are mostly unchangeable.  Existing structures on private property create unmovable barriers and  usually prevent new roads from being added to the network.  However, there is still opportunity to add pedestrian facilities that would increase a station’s walk shed in a relatively cost-effective way.

Take the example of Southern Ave Metrorail station.  We previously noted how a large number of customers drive to the station from between one and three miles away.  We discussed several reasons for this tendency to drive to Southern Ave, including the proximity to parks on both sides of the station.  The map below shows the transit walk shed of Southern Ave station.

Current walkshed of Southern Ave station.  The area with the orange dotted border contains over 1,200 households that could be within a half mile of Metrorail if a direct pedestrian connection were built.

Current walkshed of Southern Ave station. The area with the orange dotted border contains over 1,200 households that could be within a half mile of Metrorail if a direct pedestrian connection were built.

 

But what if a pedestrian path could be built to connect the station to the neighborhood to the north?

If a well lit, safe pedestrian path were constructed between the station and the orange-dotted area on the map, it could expand the walkshed to include up to 1,200 additional households in DC.  This new connection would likely increase ridership at Southern Ave. and might even generate enough additional fare revenue to fund the construction of the trail.

Metro’s Office of Planning is currently evaluating the walk sheds of our rail transit stations.  What other opportunities do you see for cost-effectively increasing the walk sheds around Metrorail stations?

Silver and Blue Line Changes: Over a Decade in the Making

June 30th, 2014 6 comments

Recent and upcoming Metrorail service changes to accommodate the Silver Line have been in the works for over a decade, and are better for Blue Line riders than originally planned.

Metrorail Service Changes with the Silver Line Opening on July 26, 2014

Read more…

Metro Riders Fight Climate Change 1.2 Million Times Every Day

June 26th, 2014 No comments

Metro provides the transit network around which a compact, low-carbon region can be framed. Without Metro available, the region would release an additional 400,000 metric tons of CO2e per year – equivalent to the carbon consumed annually by a land area approximately the same size as Fairfax County. By advocating for transit-oriented development as the region grows, Metro can continue to increase the net greenhouse gas (GHG) benefit or GHG displacement it provides to the region in three ways.

GHG Benefits of Metro

GHG Benefits of Metro

Read more…

Bus Options for Blue Line Riders

June 24th, 2014 12 comments

“If I’m a Blue Line rider in Virginia, what are my bus options once the Silver Line opens?”

16Y to McPherson Sq.

The 16Y to McPherson Sq.

We get asked this question quite a bit, and even more so now that the opening of the Silver Line is rapidly approaching.  As we have written about extensively on PlanItMetro, the start of service on the Silver Line will mean a reduction in the frequency of rush hour Blue Line trains.  Average headways will increase from 8.5 minutes to 12 minutes.  For most riders, once they arrive at a Blue Line platform their quickest ride will still be via train (even with an additional few minute wait), but there are numerous options for riders looking to switch from rail to bus or new riders looking to commute via bus.

Here are some of your best bus options if you are a Blue Line rider going to, or coming from:

Downtown DC

  • 7Y: Southern Towers to downtown DC.  Beginning August 24, the 7Y will be rerouted to pass within walking distance of these Blue Line stations:
    • Pentagon
    • Arlington Cemetery
    • Pentagon City (2 blocks)
    • Crystal City (2 blocks)
    • Farragut West
    • McPherson Square Read more…

Blue Line Riders Helped by Dedicated Signage

June 17th, 2014 7 comments

AlwaysShowBlueLinePIDSv2Some train arrival signs now always show the next Blue Line train, and it’s helping Blue Line riders determine their best route.

At rush times, Blue Line riders know they can sometimes see two or three Yellow or Orange Line trains go by before a Blue Line train arrives. For some riders, knowing just how far away the next Blue Line train is can help them decide: is it worth waiting, or should I get on the next train and transfer at L’Enfant Plaza?

To help Blue Line riders, Metro changed the arrival signs to always show the time until the next Blue Line train arrives, even if it’s more than three trains away.  That means that riders can always tell how far away a Blue Line train is, and decide whether to wait for it, or use the Yellow Line instead. Read more…

Fixing Core Stations in Metro 2025 Helps Riders from All Jurisdictions

June 12th, 2014 3 comments

Though many of the stations that Metro 2025 seeks to improve are in the District of Columbia, the capacity expansion would help riders from all jurisdictions.  

Metro needs to improve the capacity at over a dozen stations:  some of these stations are at capacity today, and our 100% eight-car train program will bring even more customers to already crowded stations.  We know we need to build new escalators, expand mezzanines, and build pedestrian passageways to meet this future demand.

The fact is that Metro 2025 is designed to benefit the Washington metropolitan area, residents of the District, Maryland and Virginia, as well as visitors from around the country and the world.

If you’re a commuter in Maryland or Virginia, it may look like the benefit of these improvements are focused on D.C. residents.   After all, 10 out of the 15 stations are located in the District of Columbia.  But the diagram below shows most of the riders who use these stations – those who create the need today, and who would benefit from fixing it – live in Maryland or Virginia.  In fact, 77% of the users of the Metro 2025 stations live in the suburbs.

 Three-quarters of riders benefiting from the station improvements in Metro 2025 live in Maryland and Virginia

Fixing core stations in Metro 2025 helps riders from all jurisdictions

Help us make the Metro 2025 projects in Momentum a reality! Learn more about Momentum, call on your elected representatives, and endorse the plan.

What’s a Transit “Walk Shed”?

June 10th, 2014 6 comments

Metro will soon be measuring how much growth happens in places that are walkable to transit. Here’s an in-depth look at how we define “walkable” to Metrorail stations and Metrobus stops.

Quarter-mile walk (by the network) for regional Metrobus stops and Metrorail stations

Areas reachable on foot from regional Metrobus stops and Metrorail stations

Metro’s new Connecting Communities metric will measure annual household growth in our region that occurs within the “transit shed” – the catchment area around transit service that generates walk ridership. And improving walkability can be an incredibly cost-effective way to reduce congestion and increase transit ridership.  Let’s take a closer look at how we defined what’s “walkable to transit.”

How Far is Walkable? First, we defined walking distance as a half-mile from Metrorail, and a quarter-mile from Metrobus, for a number of reasons:

  1. Of all the passengers who walk to Metrorail each morning, the median walking distance is just under a half-mile (0.35 miles, actually).  Riders walk farther to some stations than others, but the systemwide average is just shy of a half-mile.  Since rail riders are on average willing to walk a little under a half-mile today, it is reasonable to use a half-mile as an upper limit for walking in the future. (We don’t have similar survey data on Metrobus - yet.)
  2. The land use within a quarter- and half-mile is where we see the strongest effects on ridership on Metro today. More on this below.
  3. Academic literature supports the half-mile radius from rail transit as no better than any other distance, particularly for the link between households and ridership.
  4. Practically, setting the distance any farther than 0.50 and 0.25 miles increases overlap with other nearby stations and bus stops, which increases computational complexity. Read more…