 ating
back centuries in nautical history, the word 'headway' was originally a
contraction of the phrase 'ahead-way' representing forward motion of a
vessel, as distinguished from 'lee-way', which referred to lateral drift.
In common usage, the word 'headway' has come to mean "progress toward a
goal," and 'leeway' implies flexibility, freedom. In transit systems,
headway means the time between successive buses or streetcars or trains.
Headway ranks alongside speed as a key indicator of service
performance. Policy-makers in public transit systems
have learned that ridership decreases sharply when headways are made longer
than about 15 minutes. The psychology is elementary. Time spent
standing around waiting to get on is far more annoying (see the
The
Grumble Factor) than time spent in motion waiting to get off.
With headways less than, say, 12 minutes, planning is unnecessary; most
patrons won't even bother to consult the time-table.
Nowadays, private automobiles compete
successfully with public transportation in urban settings -- but by offering
flexibility ('leeway', so to speak) more than speed. Congestion and
parking see to that. With transit headways longer than 30 minutes,
patrons abandon public transportation and take to the automobile -- hey
in 'droves'. This, despite much higher cost for commuting by car.
For example...
| Back in 1960, a certain Inter-Mountain
community operated a successful city bus service on 15-minute headways.
Ridership expanded steadily to the point that there would be standing-room-only
for morning and evening commuters. Traffic congestion and problems
with downtown parking did not exist.
As a "common good," public transportation
systems worldwide are subsidized. In response to taxpayer complaints
about the amount of the subsidy, the city raised bus fares. Ridership
steadily expanded, though, and so did suburbia. During rush hours,
all buses continued to operate with "crush loads."
Someone got the bright idea to reduce
costs
by upgrading the fleet with bigger buses and running them less frequently.
It worked. At 20-minute headways, the city operated with 25% fewer
buses and drivers. Oh, but then, despite explosive population growth,
ridership began to decline. People bought cars.
Reduced passenger loads allowed
the city to increase headways still further -- to 30 minutes -- while selling
off buses and laying off drivers. Ridership plummeted. Soon there
were two seats for every passenger. By coincidence, cars began clogging
the streets and downtown parking-lots filled up.
Finally, at one-hour headways, the
buses ran virtually empty. A certain essayist moved into the city
in 1990 and took the bus to work every day. Often as not, he would
be the only passenger on board. He was puzzled about that. One morning,
his driver, an old-timer, reprised the headway history. |
 pproaching
the end of the Petroleum Age,
economics will doubtless become more significant in the choices people
make for their personal transportation. One might expect public transportation
systems in the U.S. to become as popular as they were a hundred years ago
-- indeed, as popular as they are today in many countries.
Private automobiles will not be
able to compete, despite all of their 'leeway', so to speak. Congestion
will become merely an unpleasant memory. Nevertheless, policy-makers
in public transit systems may have no choice but to make headways longer
and longer for petroleum-powered buses. They won't run empty, though. |
