Comparing Roads to Rail
By Jack Mallinckrodt
Light rail advocates often compare a freeway to a rail track, claiming that a rail track can carry more traffic at less cost in less space than a freeway. This is wrong in general, and true only if one compares the most heavily patronized heavy rail system (New York City) with a least utilized freeway.
The best way to avoid such selectively biased statistics is to utilize the most broadly based available national averages. For rail and roads these are the seminal annuals: Transit Profiles and Highway Statistics. The comparison is best made in terms of AVERAGE DAILY TRAFFIC, the number of persons passing a given point on a track or freeway lane per average weekday.
Freeways 1. National Average(US DOT "Highway Statistics", 1996, Table HM-72)
US Avg. Daily Vehicle Traffic on Fwys 14,179 veh/lane/day
US Avg Veh Occ. (US Census, 1995NPTS) 1.59 persons/veh
Together these give
US Avg. Avg Daily Traffic (ADT), 22,544 persons/day/lane
Freeways 2, Orange County (Ref: “1995 California State Highway Log, District 12)
Orange County Freeway Lane Miles 1480.3 ln-mi
Orange County Freeway DVMT 28,892,000 veh-mi/day
Orange County Freeway ADT 19,518 veh/day/ln
Orange County Freeway AVO 1.17 ps/veh *(Source CALTRANS)
Orange County Freeways ADT 22,836 persons/day/ln
Light Rail (US DOT "Transit Profiles", 1996 )
Annual person-miles 858.4 mill. pers.-mi/yr
Annual "unlinked" trips 249.2 mill. trips/yr
Avg weekday unlinked trips 0.8 mill. trips/day
Directional route-mi of track 562.7 track-miles
Together, these give:
US Avg Light Rail ADT, 4897 persons/day/track.
In other words, the average freeway lane carries a traffic equivalent to 4.6 average rail tracks. So a valid comparison of average person carrying capacity based on these broadest possible averages is:
One-US avg directional rail track » 1/5 of a one-directional freeway lane.
One 8 lane US Avg freeway » 40 parallel rail tracks.