填空题
The high cost of urban transportation has invariably fallen most heavily
on the poorest classes, who pay a higher proportion of family income to 62.______
transportation, and often cannot find adequate means of reaching
employment. In modern industrial centers new jobs tend to locate away from 63.______
file congested districts where the poor traditionally live.
Normally walking speed for a man has remained at about 3.1 miles per
hour at the beginning of recorded history. Horses and horse-drawn omnibuses 64.______
raised the speed of travel to approximately 6 miles per hour. Buses and
trolleys providing average speeds of 5 to 6 miles per hour in rush-hour traffic 65.______
to 12-14 miles per hour on most city streets in other time periods. Speed of
up to 50 miles per hour are often reached by buses in outlying streets of large
cities, but schedule speeds, which include stopping times, are much higher. 66.______
Studies of relative speeds of principle mid 20th-century urban-transit
modes showed average automobile speeds of up to 10 miles per hour,
compare with 16 miles per hour for suburban rail roads, and substantially less 67.______
for other mass transit. When doubtless valid statistically, such studies are 68.______
misleading because of the different functions of the different types of transit
To gain a real picture of urban transit speeds in a city like Paris or New York
would require a rationale that included a number of persons moved per mile, 69.______
how near the center of the city the movement took place, and aim station
spacing. Broadly speaking, what may be said that while speed of movement, 70.______
especially during rush hours, still leaves something to be desired in most
cities, it is as critical a problem as that of costs. 71.______