Discussing Mass Transit Part IV - Cost vs. Benefit

September 3rd, 2008 at 07:38am Common Sense Alliance 1530

How much is spent?

Comparison of expenditures for different transit systems is generally based on annual Operating and Maintenance (O&M) costs.  Capital costs, as the federal government explains, “…rise and fall…so comparison of data for various years has little value because of the differing projects included in each year.”  However, give too much emphasis to O&M expenses and you risk losing track of the real bottom line – total expenditures.

RFTA provides a perfect example of the problem of how to choose a total expenditure figure for discussion, because they spent $16 million on capital expenses in 2007, for a total transit expenditure of $37,574,000.  Average that number into the more typical rates between 2005 and 2008 (Est.), and we get a more moderate figure of $28.5 million per year.  Add in a less volatile average for Snowmass Village of about $2.5 million per year, and we can settle on an estimated $31 million annual expenditure for public transit in the RFTA service area.

What do we get?

It is often assumed that the major benefits of mass transit are reductions in both traffic congestion and fuel consumption, but there is seldom any public discussion of the amount of benefit in relation to the cost – in this case $31 million per year.

Based on a national average of four trips per person per day, total bus ridership is equal to about 4.5 percent of the trips made by the resident population of the RFTA service area.  Add any generic estimate of the trips made by second homeowners and visitors, and transit’s share drops into the middle of the three to four percent range

There seems to be an irresistible temptation to equate bus trips with vehicle trips, as though 5 million annual riders are equal to 5 million cars taken off the road.  Converting ridership to vehicle trips is not nearly that easy, and is never exact.  For example, transit creates a number of induced trips – trips that would not have been taken if not for the presence of the bus service.  Past RFTA surveys have reported that more than a third of bus passengers did not have a private vehicle available at the time of their trip.

The biggest adjustment needed to convert bus ridership into vehicle trips is made by accounting for the average 1.6 occupants that travel in a private vehicle.  This factor alone boils five million riders down into 3.125 million vehicle trips.     

Though an exact vehicle trip equivalent is elusive, we can estimate a range with a high degree of confidence.  The reduction in vehicle trips resulting from RFTA and Snowmass Village bus services is probably not less than 2 percent, and is most certainly not more than 4 percent.  Relating this range back to total expenditures, it therefore costs somewhere between $8 million and $15 million per year for every one percent reduction in vehicle trips.

In 2004, RFTA estimated the fuel savings between what the bus system consumed and what would have been consumed by their passengers had their trips been taken in private vehicles.  They acknowledged that not all trips would be converted to private vehicles, thus making this an exercise to determine the theoretical maximum rather than the actual savings.  The estimate didn’t include Rifle/New Castle service or the Ride Glenwood Springs route.  Applying this and most of their other assumptions for 2007, we show a savings of 708,995 gallons of fuel per year.

Consequently, one year of fuel savings for the major portion of the RFTA service area is comparable to the fuel consumed by just the vehicles on Highway 82 between Glenwood Springs and Aspen in 14.4 days. 

Relating this calculation back to total annual transit expenditures, each gallon of saved fuel costs about $43.72.

Any refinements of the fuel savings numbers would adjust them downward, but in this instance one factor overshadows all other considerations.  Transportation policy for the Highway 82 corridor will allow private vehicles access to only two lanes in and out of Aspen - so that the continued congestion will provide a travel time advantage for RFTA.  The Federal Highway Administration has estimated that 1.6 gallons of fuel is wasted for every hour of delay.  Fuel wasted by congestion is a national concern, but in the local context it undoubtedly offsets RFTA energy savings down to an amount comparable to one or two days of total regional fuel consumption.

There is no question that there would be far greater savings in fuel consumption with improved traffic flow than with increased transit services.

Next:  Part V

What is RFTA proposing?

Entry Filed under: Transportation, Aspen, Pitkin County