Blog The Zimride

When researching my recent post about commute stress, I came across another great finding in the study titled Leave the Driving to Them: Comparing Stress of Car and Train Commuters by Wener, Evans and Luton. This time, instead of college student participants as in the last post, researchers based this study on real commuters in New Jersey. These people traveled for over an hour (average of 75 minutes) via car or train from their homes, in New Jersey to their workplaces, in New York City.

Most interesting was the various factors tested: mood, effort, stress, unpredictability and controllability. The findings are similar to what I had initially thought, that car commuters had statistically significantly more stress, effort and unpredictability than train commuters. Trains just seem so much more pleasant than having to work through traffic when I’m a driver! Furthermore, mood was worse for car commuters than train commuters (Wener, 2006).

This continues to make me think that carpooling may be the best of both worlds – less stress, at least on the passengers and possibly less hassle especially to places where current transportation does not serve constituents well.

From the data, I created this chart that shows the effects:

Wener, R. E. (2006). Leave the Driving to Them: Comparing Stress of Car and Train Commuters. Retrieved from http://www.apta.com/passenger_transport/thisweek/documents/driving_stress.pdf.

Everyone’s always on the lookout for which is worse on the human body – driving cars or travelling via another form of transportation.  I’ve found a few good studies and one in particular showed the effect of a one-time commute. With comparative groups, including a control, White and Rotton tested cardiovascular effects of a bus, car and control (waiting room) commutes.

The effects were clear – those that drove showed increases in pulse rate and blood pressure. Those that rode via bus showed opposite effects and the commute times were essentially the same (Bus commuters took 20.0 minutes with a standard deviation of 12.97 and Car commuters took 19.4 minutes with a standard deviation of 11.2 minutes). I know I’d rather be a passenger than driving if it saves me from a heart attack!

The graphs below demonstrate the results: (White, 1998)

While some may argue that a 20 minute one-time commute is relatively straight forward compared to daily commutes that are often longer, “2 participants got lost and did not arrive at the posttest[sic] site.” (White, 1998) I hope someone found them.

White, S. M. (1998). Type of Commute, Behavioral Aftereffects, and Cardiovascular Activity: A Field Experiment. Environment and Behavior , 763-780.

Today, I read an interesting study about incentives. The Carpool Incentive Program Demonstration Project Study, outlines the results of various carpool incentive programs and shows how cash can really induce transportation mode shifts.

One of the most interesting programs was the Los Angeles Rideshare Rewards program, where “The Rideshare Rewards Program provided $2 per day for up to 3 months…in the form of gift certificates to new ridesharers.” This program seemed very successful and results are in the graph below. What was most interesting was the huge mode shift and decent retention rates after the program was finished.

But overall, the full analysis relies upon a previous study, Suburban attitudes toward policies aimed at reducing solo driving, to call out that incentives work better than disincentives. Not so fast though! Within that study it noted its own limitation: “A possible limitation of our approach could be that the stated preferences of solo drivers might not really reflect the actual behavioral change that will take place. However, the social psychology literature indicates there is a strong link between stated intentions and actual behavior…”(Baldassare)

While this may sound like a credible view, I disagree. In other studies where people were surveyed as in this study, many people that indicate willingness to change their behavior do not. For example, after people in one study indicated an interest in carpooling, they were sent carpool matching lists to form carpools. “Up to half of the people who originally indicated an interest in carpooling, indicated in a follow-up survey that they really were not interested in carpooling. The reasons for not carpooling were numerous and probably typical.”(Dueker 689)

Sources:

1. Rogers, Jonathan. Nicholas Ramfos, and Dalvamani Sivasailam. National Capital Region Transportaiton Planning Board (TPB) Commuter Connections Carpool Incentive Demonstration Project Study. January 27, 2009.

2. Dueker, Kenneth, J. Brent O. Bair, and Irwin P. Levin, Ride Sharing: Phsychological Factors. Transportation Engineering Journal, November 1977.

3. Baldassare M. Ryan, Sherry Ryan, and Cheryl Katz. Suburban Attitudes Toward Policies Aimed at Reducing Solo Driving. Transportaion: 25 99-117. 1998.

TDM programs nationwide focus on modes of transportation, offering alternatives and subsidizing various programs to solve congestion and parking challenges from too many people using their cars alone. I argue that one easy way to curb congestion is simple: Money. Throwing money at the problem can significantly reduce SOVs, and this isn’t just my MBA candidate bias coming through: there’s real proof.

Thanks to the Victoria Transport Policy Institute (VTPI), I learned all about how money changes transportation behavior. If you have time to read all 70 pages in the report www.vtpi.org/elasticities.pdf, go for it. While the report did note that “No single transit elasticity value applies in all situations,” it did find great commonalities.

VTPI discussed several models that “predict the travel impacts of a specific…program…These include the CUTR AVR Model (http://www3.cutr.usf.edu/tdm/download.htm), the Business Benefits Calculator (BBC) (www.commuterchoice.com) and the Commuter Choice Decision Support Tool (www.ops.fhwa.dot.gov/PrimerDSS/index.htm).” Most of these don’t seem that user friendly and the commuterchoice one doesn’t even seem to exist anymore. Either that or it’s painfully difficult to find.

Within this discussion of various models, I found this figure (figure 7) the most useful because it was simple and made sense. If someone pays $160 (1993 dollars) a month, less than 30% of people will drive alone. I sure would change my behavior for $237 a month (2009 dollars per www.dollartimes.com inflation calculator).

Giving money away really seemed to do the trick. “Solo driving declined 17% after parking was cashed out (employees could choose cash instead of subsidized parking), as illustrated in Figure 8.” Also, the report discussed how these impacts “increase over time.”

Just by looking at this figure, it seems like carpooling is a clear winner when it comes to cashing out. That begs the question though, can you combine cashing out with a carpool service and high impact marketing campaign to produce even better results? To my knowledge no such study exists, but from the research I’ve seen so far, I’d place a big bet on that one.