# The Problem with “Transit Gaps”

I’m in Citylab today on the subject of “transit gaps,” or “transit deserts.”  Lots of people are drawing cool maps of where transit is especially inadequate, but:

But the concept of “transit gaps” (or even worse, “transit deserts”) is less enlightening than it seems, for two reasons. First, it ignores the cost of providing transit, which has to be considered when actually doing anything about a transit gap. Second, it presents values, goals, and priorities as though they could be deduced purely from the data, which is never true.

### 5 Responses to The Problem with “Transit Gaps”

1. asdf2 February 13, 2018 at 11:55 pm #

Judging a property as located in a “transit desert” based on the distance to the nearest bus stop is shear folly. In reality, whether transit is useful or not all depends on individual circumstances that the location of bus stops on a map, alone, doesn’t come close to capturing.

For instance, a north-south bus is of no use if you want to travel east-west. And a rush-hour only bus is of no use if you want to travel in the middle of the day. Conversely, a particular spot might have lots of all-day, frequent bus routes around, but with the stop just a tiny bit further away than the threshold of the particular rating algorithm (e.g. algorithm says bus stop must be within 1/4 mile to count; actual bus stop is 0.28 miles away; algorithm pretends bus stop does not exist and calls the area a “transit desert”). In reality, one’s individual “distance threshold” depends on one’s walking ability, time constraints, and willingness to drive to a P&R to access a bus – all parameters that are unknowable to a purely generic algorithm. And worst of all, of course, is a “mode bias” in an algorithm, which promotes streetcars over buses, simply because the streetcar runs on rails.

• Sailor Boy February 14, 2018 at 1:11 pm #

+1, the algorithm has values that are miles away from most transit riders!

• Novacek February 15, 2018 at 6:54 am #

+1

Or willingness to ride a bike (and whether there’s supporting bike infrastructure). Or those little electric scooters or skateboards they have now.

Conversely, a stop could be .2 miles away and completely unwalkable.

• el_slapper February 15, 2018 at 7:21 am #

The walkability is especially important. Montpellier’s tramways does not stop far from the airport, but the walk is especially unfriendly and dangerous. There is a dangerous roundabout that links the nearby motorway, and you have to walk in an uneven grass for half of the distance.

2. el_slapper February 15, 2018 at 7:22 am #

The walkability is especially important. Montpellier’s tramways does not stop far from the airport, but the walk is especially unfriendly and dangerous. There is a dangerous roundabout that links the nearby motorway, and you have to walk in an uneven grass for half of the distance.