Blog The Zimride

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