A Caveat in Commuting Data

Tags: , ,

A Caveat in Commuting Data

Recent commuting data reported by the Valley Business Front has some good news with one caveat.


A December “By the Numbers” column in Valley Business Front had some moderately positive news about commuting behavior in the region:

[R]ecent figures from the 2007-2011 American Community Survey…show a very slight drop in percentage of solo commuters in the region, and a very slight, possibly corresponding, rise in commuters using public transportation.

The column’s author, Anne Piedmont, goes on to state that 81.1 percent of commuter are single occupancy vehicle travelers – they drive alone – while 1.5 percent of commuters use public transit.  She doesn’t report on bicycle commuting, though this number – while increasingly rapidly – is still a tiny fraction of the total mode split in the region, less than 1%.

She also points out that rate of transit use is lower in the Roanoke region than elsewhere in the state, even taking into account that transit isn’t available everywhere.  This is an important point and something to be skeptical of when people cite national or statewide numbers on transit use or bicycle commuting – the vast majority of localities in Virginia and beyond don’t have a transit option available to them, yet that total population serves as the denominator when the Census determines mode split percentages.  It can give a skewed perception of how popular transit can be in areas where it is available.

While this data is positive, there is a caveat I wanted to mention that may understate some of what’s happening in the region.  The American Community Survey simply asks respondents “How do you usually get to work?”  The wording undercounts folks who may ride bikes, carpool, or take the bus one or two days a week, but still consider driving alone how they “usually” get to work.  In the Roanoke Valley, a lot of bicycle commuters put their bikes away for the cold fall and winter months, which can further understate the number of bike trips being taken.  Finally, the question ignores all other trips – someone may drive to work most days but ride their bikes to market or take the bus to visit friends.  None of these transportation dynamics are captured the data.

The data is good news and shows we’re making progress, but it doesn’t tell the whole story.

Leave a Reply

Your email address will not be published. Required fields are marked *

Translate »