Adaptation Strategies for Managing Recurring Congestion—Operational Improvements - Road Traffic Congestion - page 224

it is anticipated that congestion relief bene ts from the ICM strategy will be

￿

greater than the bene ts of individually applied strategies as demonstrated by

the application of a similar approach in Europe (Active Traf

c Management)

that uses:

Speed harmonization : reducing speeds in advance of a major bottleneck to
minimize the impact of the congestion event and increase overall throughput;

-

Temporary shoulder use : using the shoulder of the roadway in conjunction
with speed harmonization, to increase capacity during peak periods;

-

Queue warning display systems : to warn drivers of the presence of con-
gestion downstream;

-

Dynamic merge control : the selective closing or metering of ramps based on
traf

-

c demand to maximize throughput, with priority given ramps with
higher volume;

Dynamic routing and traveler information : the use of dynamic message signs
to display rerouting instructions in response to non-recurring congestion
events; and

-

- Dynamic lane markings : the delineation of lanes to manage traf c fl ow

patterns created by the above strategies.

- Transit-Traf c operations

in both arterial streets and freeway corridors to reduce delay for all travelers.

c Integration : the coordination of transit and traf

16.12 Conclusions

The various operational (e.g., c engineering) strategies described in this

chapter, where effectively and sensibly applied, will reduce congestion delays in
most urban areas.
A general description of various strategies, and an assessment of their applica-
tion, effectiveness, and implementation issues is given in Table 16.10 . This table is
adapted from a national research project conducted by Cambridge Systematics [ 23 ].
The resulting bene

traf

ts of operational strategies that reduce recurring congestion,
however, will probably not meet the long term needs of many cities. Growth in
person travel in the rapid growing areas of the

United States will require additional congestion relief strategies and actions.
Accordingly, Chap. 17 describes roadway capacity expansion strategies and Chaps.
18

— motorized travel in particular —

- 23 describe strategies that reduce traf c demand.