Millions of people each day turn to books, yoga, prescription meds, and other tools to de-stress their lives, but maybe they should rideshare instead. After scouring research into commuting and stress, the paper “Mitigating the Stress of Commuting to Work: Ridesharing and the Interactional Effects of Gender” by Novaco and Sandeen point out that “ridesharing has some stress mitigating effects…” (Novaco 1992) Ridesharers included participants that either commuted via carpool or vanpool.

This report yielded many insights including gender differences and the differences between rideshare drivers, rideshare passengers and solo drivers. There’s some evidence that ridesharers get some great benefits vs. solo car drivers. For example, mean arterial pressure for solo male drivers was 95.9 vs. male rideshare passengers reading of 87.6.

From an employer’s perspective, the job involvement scores were clearly much higher for all ridesharers. See the graph below:

An added bonus to rideshare employees is that they are more accurate in some work tasks. For example, this study conducted a proofreading test and found that both rideshare drivers and passengers were more accurate than solo drivers.
While not all metrics pointed out that rideshare drivers were better off than solo drivers, rideshare passengers seemed to almost always show clear benefits. From now on, I’ve decided that ridesharing is a clear benefit to me and my fellow employees, and I might just volunteer to drive one day to get all the great benefits for 4 other days of the week.

Novaco, R. and Sandeen, B. (1992). Mitigating the Stress of Commuting to Work: Ridesharing and the Interactional Effects of Gender.

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.

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.

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.

Over the next few weeks, I aim to uncover the dust from all those great 1970s carpool studies and discuss how they do or do not relate to life in 2009. Finding this research has taken me from the basement of Stanford’s library to days of internet searches to uncover all the best carpooling academic literature. My grad professors would be proud; they pounded the tables about the importance of data.

Even before starting at Zimride this summer, I wondered if carpool services were worthwhile. Do they help the environment? Are they effective at saving people real sums of money, reducing congestion, or making life more pleasant? Would they pair your grandma and the lead singer of Metallica? Let’s hope not! Or poor Tessa would surely get a few more “customer service” phone calls. We all know how those old rideshare boards, don’t get much use. Out of 50k students at my Alma Mater, I don’t think there were ever more than 10 postcards for rides on the ride board. For all you whiz kids, that’s 0.02%, certainly a number that would get any TDM (Transportation Demand Management) director fired. Just to settle things, Zimride does a lot better than matching 10 rides per university!

Rideboards: 0 Zimride: 1

Then I looked for support in ivory tower research. It’s always best to start with summaries, that’s why you’re here, right? A great first start into understanding ridesharing was “The Determinants of Ridesharing: Literature Review” by Keith Hwang and Genevieve Giuliano (School of Urban and Regional Planning, University of Southern California, Working Paper, May 1990). These guys did a bunch of leg work for me, although my legs are getting pretty buff from biking 6 miles a day to/from the local Caltrain station to get to work!

A big ah ha moment came to me when I read “With matching services, employees rideshare approximately 10 percent more than without it within each size category of firm.”

Then I saw the data of how employees get to work at employers with over 10,000 employees. Only 11.15% of employees at firms without matching programs participated in ridesharing vs. 24.23% of employees at firms with matching programs. That’s a huge difference!

Single occupancy vehicle participation rates were also striking: 85.81% at those without matching programs vs. 74.74% for those with matching programs. Ok, so you’re probably thinking to yourself, those firms without matching programs probably have different efforts focused on TDM. Well, the participation rates of public transportation would be vastly different if that was the case. However, that’s not the case; public transit participation rates were 1.95% for firms with matching programs and 1.91% for firms without matching programs.

Case closed. Matching programs work and work really well.

Note: the above data was originally published by Ferguson, E. (1990a) “An Evaluation of Employer Ridesharing Programs in Southern California.” Transportation Research Record. 1280.

I’m on a mission, to find out all there is to know about carpooling. As a Zimride intern, this summer, I’ve already learned amazing TLAs (Three Letter Acronyms) and fun facts about carpooling. In the next few weeks, I’ll be posting about the most interesting tidbits and research that I come across. This way, all you zimriders and TDM professionals will benefit too.

First up – Commuter Calculators. I have to credit the amazing Tessa with giving me advice during my first week about the costs of driving. It seems that cars cost much more than people think. I used to think that Philly Car Share was a bit expensive at $5 an hour + mileage. That was until she broke down all costs of driving a car around. Maintenance, insurance, taxes, gas, parking and depreciation all add up to a lot. But you don’t have to be a math major or even know what the word quantitative means to figure out what this costs. Of course, some of those costs are sunk costs (for all you finance people), but a lot of it isn’t. Commuter calculators can easily help you understand if it’s cheaper to take light rail (I take Caltrain and love it), public transportation, bike, vanpool or carpool.

So, I ventured to a slew of sites to compare them. For each one, I used my commute (60.8 miles round trip) as an example even though I don’t own a car. I used current national gas prices as of June 16, 2009 ($2.674/gal) and estimated other costs and inputs (25 MPG, commuting 5 days a week, $0 in parking). Here’s my ranking and breakdown of various sites that help you calculate the cost of driving:

1. Rideshare SLORTA Driving Cost Calculator

The best of the bunch! Easy to use and nice drop down boxes helped me choose what type of car (I choose compact). It also suggested different MPG (Miles Per Gallon) based on what type of car I chose! As an added bonus, it yields the most specific pollutant breakdown by spelling out how many lbs of carbon monoxide (CO), nitrogen oxide (NOx), and hydrocarbon (HC) pollutants are emitted. The only downsides I see are the insurance and depreciation costs, which seem to be left out entirely.

Daily Commuting Cost: $20.18
Monthly Commuting Cost: $403.61
Annual Commuting Cost: $4843.38

2. CommuteWorks Caluclator

This one was the quickest and easiest of the bunch. Simply pop in roundtrip mileage and monthly parking, and it spits out some number. I thought this one would be totally off base, but it seemed to get an estimate that fell somewhere in the middle.

Daily Commuting Cost: Not Given
Monthly Commuting Cost: $657.72
Annual Commuting Cost: Not Given

3. Denver Regional Council of Governments RideArrangers

I really liked this one. It gave me estimates for the items I didn’t know, depreciation for mile based on how old the car is and estimated oil, maintenance and tires at a reasonable 5¢ per mile. However, it left out insurance, which I could include by adding it into my depreciation cost per mile input. But, my insurance company insists that it cannot quote me a rate based upon mileage. My insurance company only quotes 6-month policies, not mileage based ones – doh!

Daily Commuting Cost: $20.49
Monthly Commuting Cost: $409.74
Annual Commuting Cost: $4916.92

4. University of Virginia Parking & Transportation Commuter Calculator

This one was fairly comprehensive and easy to use, but it did not include insurance or depreciation costs. Also, it adds in Charlottesville personal property taxes, which is great if you live in Virginia, but I don’t.

Daily Commuting Cost: $7.02
Monthly Commuting Cost: $129.87
Annual Commuting Cost: $1684.31

5. Schoolpool Cost Calculator

Schoolpool’s got a nice layout, all in the same table, but the font is tiny! Then, there are the results, I was pretty shocked when I saw these. It estimates two big factors, maintenance/taxes and insurance/depreciation at what I thought were pretty high rates, 6.5¢ and 46¢ per mile. As an added bonus, this one gave me CO₂ emissions of various car types (Midsize was 881lbs of CO₂).

Daily Commuting Cost: Not Given
Monthly Commuting Cost: $768.46
Annual Commuting Cost: $9,221.56

6. SEPTA Commuter Calculator

SEPTA may have got the right number of variables in here to make it easy, but also customizable. It asks for 6 different numbers, but suggests all of them. I’m not sure where they get a $1.99 cost for gasoline. Here’s a suggestion, link this metric to the gas rate in Philly. At phillygasprices.com I found the lowest rate was $2.55; I think 56¢ would change the cost of my monthly commute, at least by a bit.

Daily Commuting Cost: Not Given
Monthly Commuting Cost: $640.78
Annual Commuting Cost: Not Given

7. Harvard University Commuter Cost Calculator

It’s hard to really know what the kids at Harvard are doing when it comes to this calculator. If they are shooting for higher is better, they knocked Schoolpool out of the running for highest estimates! For those at Harvard, this one does include cost comparisons to public transportation with Harvard subsidy added in. This engine estimates the costs of gas, oil, maintenance, tires, insurance, taxes, depreciation and finance at 51¢ per mile per AAA. For all the environmentalists, stay away from this one – It estimated that I would emit 15,321lbs of CO₂!

Daily Commuting Cost: $39.48
Monthly Commuting Cost: $829.08
Annual Commuting Cost: $9,946.02

8. New Jersey State Calculator

With only 4 numbers to input, 9 new numbers are created and that doesn’t include the matrix of potential savings (20 more numbers). If you don’t like inputting numbers but love data, this is the one for you. Although, it estimates insurance, depreciation, maintenance, etc. at some rate that it doesn’t spell out.  Since that number makes up 75% of the total costs, I’d like to know exactly what that stuff is.

Daily Commuting Cost: $23.95
Monthly Commuting Cost: $661.64
Annual Commuting Cost: $7,939.68

9. Metro Area Transit (Omaha, Nebraska)

The estimates might be ok, but it was the most confusing of the bunch. I found it difficult to even understand what my cost was.  Instead of one number, it gives a  savings table based upon how many days you would ride public transportation.

Daily Commuting Cost: Not Given
Monthly Commuting Cost: $674.18
Annual Commuting Cost: $8,054.20

Summary: There are way too many commuter calculators and none of them are that great! To get the full picture, you would have to track how much your car costs you, add in insurance costs, and use actuarial statistics to know the best estimates for depreciation costs. But, in a pinch, these seem to all hover around similar numbers.

Here’s an average of all the calculators:

Daily Commuting Cost: $28.79
Monthly Commuting Cost: $575.81
Annual Commuting Cost: $6,909.71

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