Gaithersbungle, part 7: 30% mode share is totally unrealistic
The Gaithersburg West "Science City" Master Plan hangs its "Smart Growth" claims on the Corridor Cities Transitway, a proposed transit line from Shady Grove northward to Gaithersburg and Germantown. The plan insists that 30% of commuters will ride the line. That's highly dubious. You can design a circuitous, low-quality transit line and claim many people will ride it, but that doesn't make it so.
To satisfy the political pressure of enabling development on every parcel, the Planning Department proposes rerouting the line from an already-circuitous route (red) to an even more circuitous one (blue). This reroute took the line away from the DANAC property, whose owners originally developed it with the promise that they would have a CCT stop. The published draft of the Master Plan, however, eschews any new development on DANAC's property. After the owner complained and put pressure on the board, they added a stop back in.
The Planning Department also recommended BRT over light rail, claiming it would actually draw more passengers because buses can leave the transitway to circulate through nearby neighborhoods. Rerouting the line through more of the office parks in Gaithersburg West also added riders under the Planning Department's model. Without seeing the underlying models, there's no way to know how they arrived at this result or whether it's correct, but it sounds like the model assumes that more frequent stops on a more circuitous route that passes closer to people's homes will draw more riders than a faster route that connects major, dense centers.
The plan claims that Gaithersburg West will achieve a 30% mode share between the density, transit, and Travel Demand Management (TDM) programs. According to a Fairfax County presentation on Tysons Corner, the Rosslyn-Ballston corridor's mode share is 26%, Bethesda's 19%, and downtown DC's 51%. Achieving 30% in this distant, auto-dependent area with buses following a long and winding route seems highly dubious.
According to the Action Committee for Transit, planners arrived at 30% by assuming that the mode share will match White Flint. However, White Flint is right atop a Metrorail station, closer to the region's core, and very close to many more jobs. It also assumes that 24% of people will carpool, while the current actual number is approximately 5%, and carpooling has declined regionwide in recent decades. According to ACT, COG's modeling of this area predicted that 8% of people will actually take transit to work absent residential development, and there is far too little residential development to boost the number anywhere near 30%.
Nor does the plan enforce that 30%. The staging requirements do mandate that most of the development can't happen until the CCT is at least funded and under construction, but that's no guarantee anyone will use it. If the County wanted to truly enforce the 30%, they could allow the development only if mode splits are really meeting the projections, or impose impact fees on the new development if they don't.
Critics have charged that JHU isn't really serious about building a research campus at all, but that they rather want to make a lot of money on turning their farm into an office park to fund their main operations in Baltimore. We don't know for sure if that's the case. But if it is, and the 30% mode share and everything else are just a smoke screen, the County Council should put some teeth into the 30% requirement, enough that building an office park without that kind of mode share ceases to be a cash cow for JHU.
A county could develop a bus system that stops at 20 people's individual houses, drives for 30 minutes, then drops them off one by one at their jobs, and call it BRT. They could then spend billions to make a very wide expressway and lots of interchanges to speed drivers. And finally, they could write a plan that claims that one-third of the people will ride this transit system. But we would laugh. And that should be our reaction to this plan as well.
- Part 1: Planning Board staff latest to ignore better way for Gaithersburg
- Part 2: Old, tired formulas generate old, disastrous solutions
- Part 3: What else can you get for $3.8 billion?
- Part 4: Why emulate Tysons' existing road network?
- Part 5: What you callin' a city?
- Part 6: What else $3.8 billion could buy, more specifically
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