By on 10.28.13 in Transportation

In 2012, 80% of U.S. commuters drove alone to work. In the push to reduce traffic congestion and vehicle emissions, as well as improve quality of life and health outcomes—both physical and fiscal—for commuters, many are encouraging car alternatives. The city of Chicago, for example, recently launched its “Drive Less, Live More” campaign, which advocates increased public transit, biking, walking, carpooling and car-sharing, and telecommuting, with the promise of “Less traffic. More air quality. More smiles.” Similar efforts are underway locally with the Go Triangle partnership between public transportation agencies and organizations to “enhance the quality of life in the region and improve accessibility…while reducing roadway congestion, air pollution, and oil consumption.”

TTA_bus02

Compared to neighboring Durham and Wake counties, Figure 1 shows Orange County commuters are much less likely to get to work in single-occupancy vehicles: 71% versus 78% and 85%, respectively, according to the 2012 American Community Survey (ACS). One in every ten Orange County commuters uses public transportation to get to work. Another 5% walk to work, 4% ride a bike or motorcycle, and 10% participate in car or vanpools.

Figure 1. Mode of Transportation to Work among Orange, Durham, and Wake County Commuters, 2012 ACS

Mode of Transportation among Triangle Area Commuters, 2012

The ACS provides information about workers’ current commuting patterns. But, given the potential importance of reduced reliance on cars for both individual workers and the broader community, we wanted to answer the question “How many Orange County workers could theoretically take the bus to work?”

To examine this, we used data from the U.S. Census Bureau’s Local Origin-Destination Employment Statistics (LODES) data. While lacking detailed information on social and demographic characteristics, means of transportation to work, and other commuting attributes, this is the only publicly available data set to provide detailed information on home-to-work commuting flows. LODES data are available at the Census tabulation block and can be summarized to provide detailed origin-destination data for almost any geographic region.

The interactive map below shows county-to-county commuting patterns among Orange County workers employed within the state. The majority of commuting destinations are within Orange (36%), Durham (25%), and Wake (13%) counties. Additional large flows occur westward on the I-85/I-40 corridor into Alamance, Guilford, and Forsyth counties and south into neighboring Chatham County. Large flows into further flung counties, such as Mecklenburg, New Hanover, and Transylvania, may reflect legitimate long-distance commutes, as well as commuter marriages, telecommuters who live (and work) in Orange County for an employer elsewhere in the state, and non-reporting of detailed worksite location by employers in the data.

Map 1. County-to-County Worker Flows, Orange County Workers Employed in NC, 2011 LODES

View Larger Map

Next, we pulled information on bus stop information for the four major transit systems connected to Orange County either directly or through transfers: Chapel Hill Transit, Durham Area Transit Authority, Capital Area Transit, and Triangle Transit. A general rule-of-thumb is that individuals have access to a bus stop if it is within a quarter mile walk. Lacking individual addresses, there are many different ways to perform a spatial analysis to classify blocks. We minimized complex assumptions and used a fairly conservative classification metric: a block was classified as being within a quarter mile of a bus stop if its centroid (the middle) was within a quarter mile of the bus stop. Individuals whose home block and work block were within a quarter mile of a bus stop were classified as being capable of using public transportation to get to work.

Table 1 shows the results of this analysis. Nearly 25% of all Orange County workers both live and work within a quarter mile of a bus stop. Half of Orange County workers have access to a bus stop at either their residence or at work, but not at both, and another quarter neither lives nor works near a bus stop. Looking only at Orange County workers that work within the four counties connected by bus stops dramatically increases these percentages: 33% of commuters within the Triangle region live and work within walking distance of a bus stop.

Table 1. Orange County, Access to Public Transportation by Employment Destination, 2011 LODES

Orange County Access to Public Transportation by Employment Destination

One major factor that we could not account for in this analysis was the existence of Park and Rides; 40% of Orange County workers who commute within the Triangle work near a bus stop, which means they might be able to take a bus for part of their commute if they used a Park and Ride. Based on this analysis, more than half of all Orange County workers—and nearly three-quarters of those that commute within the Triangle—could potentially take a bus for their entire trip (bus access at both home and work) or a portion of it (Park & Ride).

Potential ability to use public transportation does not necessarily mean that people use public transit, of course. Based on this analysis, more than 15,000 Orange County commuters could potentially ride the bus to work, and another 18,500 might be able to take the bus for a portion of their commute. In 2012, just over 6,000 Orange County workers commuted via public transportation, a gap of 9,000 (to 27,500) individuals who could potentially use public transportation but don’t currently do so.

Public transit may be time-consuming and inconvenient, with multiple transfers or transportation times that do not align with work schedules. Cars offer flexibility and convenience for coordinating work with other activities and responsibilities, such as taking care of children, running errands, or balancing multiple jobs. While this analysis gives an idea of current commuting flows and basic public transportation infrastructure, it cannot fully address practical considerations (and habit) that may ultimately be more important to commuting decisions than access alone.

Your support is critical to our mission of measuring, understanding, and predicting population change and its impact. Donate to Carolina Demography today.