Post #447: NVTA, fix your cost-benefit calculation

Posted on November 7, 2019

The title is the most polite thing I can say about the Northern Virginia Transportation Authority (NVTA), and paying for Vienna’s parking garages.  But I think it tells us something about Town of Vienna government as well.


In my last post, I laid out what’s happening with the funding of the proposed Patrick Henry Library garage.  This parking garage will likely be built in 2022 or so, when the County replaces the Patrick Henry library with a bigger building.

In terms of funding: In a nutshell, Vienna is asking the Northern Virginia Transportation Authority (NVTA) to give us a free garage.  And more.  The Town’s capital spending plan calls for NVTA to pay for all of the Patrick Henry garage, and to pay for most of yet another garage that the Town plans for the intersection of Church and Lawyers.

The problem is that both of these garages are for shoppers and diners.  They are there to provide parking for the local merchants.  And the NVTA has absolutely no business spending the taxpayers’ dollars to build those.

But somebody on Town staff got the bright idea of making up a story about a possible use of the garage, as a way to provide a veneer of acceptability to NVTA.  The story is that we’ll allow commuters to park there.  And that commuters will  drive to the middle of Vienna, park, and walk or take the bus to Metro.

I’m not making that up.

Now, that’s obviously nonsense.   Commuters aren’t going to fight their way to the middle of Vienna, during rush hour, so that they can park and then take the bus to Metro.  You can assess that logically, as I did in my prior posts about the Mill Street garage.  Or …

Are you sure that’s nonsense?  Yes.

We have a market test of that right here, right now.  Why?  Because, right now, there are plenty of places around Vienna where you can park on the street and take a bus to Metro.  We already have plenty of public parking where a commuter could drive into Vienna, park and take a bus to Metro.  And nobody does that.  So we already have real-world evidence that the story the Town is spinning is nonsense.

Looking at a map of bus stops and streets (per the picture above), I count at least the following residential areas, with street-side parking, within walking distance of a bus stop for the 463 Fairfax Connector bus:  Kingsley-Meyers; Tapawingo; Roland-Mendon-Ceret; Moorefield-Princeton-Princess; Wade Hampton-Millwood-Glen; Pleasant; Berry; East; and virtually all the residential streets beyond East that connect to Maple.  That isn’t even counting the other bus routes that have some Metro connection.

I’m not going to count the number of open slots in the morning, but I would bet that, on any given weekday morning, we already have far more than 181 public parking places, available to anybody who wants to drive into Vienna, park, and catch the bus to Metro.  And, again, near as I can tell, absolutely nobody does that.  Or, at least, I have never heard the complaint that Metro commuters are parking up a neighborhood so they can get access to the local bus stop.

As far as I have heard, the only place where you see people park in Vienna to get to Metro is in the Marshall Road area, where they can walk to Metro.  Otherwise, we have vast residential areas with unrestricted parking and easy bus access to Metro.  And nobody drives to Vienna, parks there, and takes the bus to Metro.

The upshot is that we already provide ample opportunity for anyone who wants to drive to Vienna, park, and take the bus to Metro.  Nothing stops you from doing that now.  The idea that people will do that from a parking garage at Maple and Center is clearly bunk.

So how did NVTA approve spending money on this?

Wait, what do you mean approve?  Isn’t this up for grabs?  Doesn’t there still have to be some review?

Well, yes and no.  The NVTA approved the exact same argument, when the Town made it about the (defunct) Mill Street parking garage.  In fact, it still appears to carry the Mill Street garage on its books, as an active project.  In among all those serious projects — interchange improvements, road widening, additional bus service, and so on — there squats $2.3M approved for paying for half the cost of the Mill Street garage (60 parking places).  That works out to $38,000 per parking space, based on this ludicrous argument that those spaces would be used by Metro commuters.

Here’s where it gets weird.  If you look closely at the approval of the Mill Street garage, NVTA staff cover their butts on it.  You can find a summary of the approval at physical pages 130 and 131 of their six-year report (.pdf)).  They repeat the nonsense about commuter access, but they add this little disclaimer:

Note: The regional impacts listed above are a summary of what was submitted in the project application NVTA staff received from the jurisdiction or aagency that has applied for funding.

In other words, they simply accepted whatever Town of Vienna chose to tell them.  Which means that as long as the Town of Vienna is willing to lie with a straight face, we can bilk them for the cost of our shoppers’/diners’ parking garage.  They expect local governments to provide honest analysis, and they apparently accept whatever we tell them, at face value.

They appear to have nothing in place to weed out cheats and liars. And that provided the loophole that the Town successfully exploited before, with the Mill Street Garage.  There’s no obvious reason that the Town won’t get away with it again.

But wait, there’s more …

In fact, if you look at the dollars, NVTA was willing to pay $38,000 per imaginary commuter parking place at Mill Street.  Here, shoot, the Town is offering them an imaginary bargain by comparison.  The current proposal works out to a mere $31,500 per imaginary commuter parking place.  And you know what?  Because it’s cheaper, when they once again take our lies at face value, they’ll give us a higher score for this one than we got the last time.

Hey, I have a great idea.  Let’s save the taxpayers even more money, on these imaginary commuter parking places.  I have a big driveway.  Three cars could easily park there.  I’m within walking distance of a bus stop.  If the NVTA will give me a mere $15,000 per parking place, I’ll make my driveway available to all the imaginary commuters who would want to park in Vienna and take the bus to Metro. 

Heck, let’s just crowd-source the whole thing.  First 181 people in Vienna who live within walking distance of a bus stop, and will offer up their driveway space to imaginary bus commuters, can each collect $15,000 from NVTA.  That way, we’ll have provided just as much parking for the imaginary bus-to-Metro commuters as the Town will, at a fraction of the cost.  And since there’s no need to wait for construction, we’ll reap the imaginary traffic congestion relief benefits immediately.

Why not?  It’s clearly a win-win situation.  If … and only if … you’re stupid enough to believe the park-to-bus-to-Metro argument in the first place.  NVTA isn’t being stupid per se, they just assume that local governments will tell them a straight story.  But that, in and of itself, is a fairly stupid thing to assume when you are dealing with the Town of Vienna.

Am I missing the point with my crowdsourcing idea?  I don’t think so.

I can hear people saying, “But that misses the whole point.  Sure you could distribute the imaginary commuter parking all over town.  But that doesn’t get us the shoppers’/diners’ parking for free”.

The first point is that everyone who thought that, as they read the prior section, implicitly understands that we are getting our garage paid for under false pretenses.  Our Town staff are abusing the system, with this ridiculous argument about commuter parking, in order to obtain taxpayer funding that we have no right to, from an organization that has no business funding merchants’ parking.

My second point is that maybe this isn’t what we want the Town of Vienna to be.  Cheating a system that isn’t set up to catch the cheats, so we can grab some free tax dollars.  Is that what “small-town Vienna” is all about these days?  Or, as long as we get that free money, is anything OK?

My third point is that “free” is a four-letter word.  At least to economists.  If we had to pay for this out of our own funds, we might (e.g.) actually take the time to estimate how many parking places we really need. Actually think about it before we spent the taxpayers’ money.  But free?  Crap, if it’s free, why not build as many parking places as will fit on the lot?  Which, despite protests to the contrary, is exactly where this is headed.

So a “free” shoppers’/diners’ garage — improperly paid for by the NVTA — will equate to having the centerpiece of the Town of Vienna being the largest possible parking garage that they can squeeze onto the lot.  Ah, with a library attached, somewhere.  Just wait and see.

But ultimately, Fairfax County has the final say over the library design.  Please, Fairfax County, save us from our folly.

Addendum:  Include an expected utilization factor in the cost-benefit calculation.

On a more scientific note, I think the problem is that the NVTA cost-benefit calculation is being done wrong and needs to be corrected.  In order to figure out what they are actually getting from this expenditure, they need to add in a realistic expected utilization factor.   That is, a factor to account for the fraction of available spaces that they actually expect to be used by people who want to drive to Vienna, park, and take the bus to Metro.

They aren’t actually buying 181 spaces that will be used by commuters.  And so, their cost-benefit calculation should not assume that.  If it does, it’s wrong.  It needs to assume that some fraction of the 181 will be used that way.  And I strongly suspect that the lack of a realistic expected utilization factor is what leads them to approve funding for a project like this, when they clearly should not.

I think that correct expected utilization factor is 0%, but one could reasonably disagree.  I’m sure that factor is not 100%, or, per my prior reductio ad absurdum post, the garage would be worthless to Vienna. 

And failure to include any such factor is equivalent to an assumption of 100% utilization.  Which, per above, I am quite sure is wrong.

So, if you expect (say) five percent of those spaces actually to be used by Metro commuters, then the cost per car taken off the road becomes 20 times (1/.05) higher.  I am confident that the inclusion of any realistic expected utilization factor would show that this garage is a ridiculously costly way to reduce traffic congestion, and so would prevent NVTA from funding it.

As a final note, when I cited $38,000, $31,500, and $15,000 above — those calculations implicitly assumed an expected utilization factor of 100%.  And I bet you didn’t even stop to think about it — you just accepted those numbers based on the long division.  And I bet that’s exactly what NVTA did as well.  But if the actual utilization rate is zero — if nobody ever wants to park in my driveway and walk to the bus to get to metro — then the cost per space actually used is infinite.