Civil Engineering Reference
In-Depth Information
Adding new mixed use lanes to existing highways to serve additional personal
travel demand
and
truck freight traf
c, might not solve the twin safety and con-
gestion problems associated with the mixing of truck and car traf
c. Crashes
involving large trucks affect congestion dramatically, and approximately 12 % of all
highway
related fatalities involve large trucks [
20
].
Truck-only facilities provide safety bene
—
ts by separating cars from trucks in
heavy truck corridors (e.g., sections of the NJ Turnpike). They also serve to provide
the
flexibility/redundancy when a crash or other disruption in one roadway requires
the rerouting of traf
fl
c.
In some situations, segregated truck-only roads might be desirable. Similar to
bus and high-occupancy vehicle lanes, truck lanes/roads will need special access.
Truck ways reduce congestion on parallel heavily traveled freeways and arterial
roads. However, constructing additional truck lane capacity that is not fully used in
peak hours, while the adjacent mixed use lanes are congested, could lead to political
problems from users of congested lanes.
17.3.3 Freight Intermodal Access Roads
This strategy involves the construction of new roads or improving existing roads to
improve travel time and reliability of truck traf
c serving major freight/intermodal
terminals. Linking intermodal facilities, warehouses, and highway interchanges can
provide increased ef
c locations in a metro-
politan area. In center cities intermodal access improvements are of a multimodal
character (consisting of local streets connecting to the intermodal facility and of
arterial highways that connect to the freeway network).
ciency in goods movement for speci
17.4 The Issue of Induced Traf
c
17.4.1 What Is Induced Traffic?
“
is a widely used term among professionals that describes the
observed increase in traf
Induced traf
c
”
c volume after the capacity of an existing road is increased
by operational improvements, or when new capacity is added by roadway widening
or the construction of a new road. It is used by transportation planners in sizing new
or improved roads, and also by advocacy groups that are usually opposed to
roadway expansion.
As stated in Ref. [
21
],
The term often appears in the popular press, and has been
used by some advocacy groups to support their argument that
“
'
we can
'
t build our
'
way out of congestion,
because any increase in highway capacity is quickly
filled
up with additional
traf
c.
…
the term is often is often misused to imply that
