Civil Engineering Reference
In-Depth Information
Suburban area
(a) Distance traveled at 12 mph for a 30 min trip = 6 miles
(b) Destination opportunity area reachable by bicycle = 113 square miles
(6
×
6
×
3.14).
3. Destination Opportunity area accessible by Bus (assuming two intersecting
bus routes)
Urban Area
(a) Distance traveled at 12 mph, for 17 min (30
13 min) = 3.4 miles
−
(b) Destination opportunity area by bus = [(3.4
×
0.5 miles)
×
2]
×
2 routes = 7 square miles.
Suburban Area
(a) Distance Traveled at 15 mph, for 12 min (30
−
18 min.) = 3.0 miles
(b) Destination opportunity area by bus = [(3.0
×
0.5 miles)
×
2]
×
2 routes = 6.0 square miles.
4. Destination Opportunity Area Accessible by Private Motor Vehicle
Urban Area
(a) Distance traveled at 20 mph for 24 min (30 min. door to door travel
time-6 min. excess travel time) = 8 miles
(b) Destination opportunity area reachable by motor vehicle = 201 square
miles.
Suburban Area
3 min.) = 13.5 miles
(b) Destination opportunity area accessible by motor vehicle = 572 square
miles.
(a) Distance traveled at 30 mph for 27 min (30
−
These results in rank-order are shown in Table
11.1
.
Example 2
Another measure of spatial accessibility is a mapping of the area accessible by each
mode as a function of travel time. Travel time contours can then be developed for
each mode and the area accessible within a desirable travel time (i.e., 30 min) can
be used to compare the accessibility provided by each mode. An illustrative
example is shown in Fig.
11.3
.
Alternatively, door-to-door travel times for a given trip distance from a major
focal point, such as the city
'
s central business district (CBD), can be estimated for
each travel mode. As shown in Fig.
11.4
modal door-to-door travel times are
