PURPOSE OF PROPOSED PROJECT
The purpose of the proposed project is to provide
a transportation facility that properly
addresses existing and projected system
deficiencies and seeks to improve the safety and
efficiency of the transportation system in
northwest Illinois. The US Route 20 improvement
would provide a high-type highway with an
appropriate connection to the four-lane facility
west of Illinois Route 84 (northwest of Galena)
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47 miles to the east connecting to a previously
approved four-lane facility near Freeport. This
improvement and the Mississippi River crossing
(Julien Dubuque Bridge) are the only remaining
two-lane sections of US Route 20 left to be studied
for multi-lane improvements between Waterloo, Iowa
and Rockford, Illinois. |
NEED FOR PROPOSED ACTION
The need for the proposed project is based on
several aspects of the currently inadequate
transportation system. The study addresses the need for
the proposed action in terms of regional economic
characteristics, system capacity, safety concerns,
community access, and system continuity.
REGIONAL ECONOMIC
CHARACTERISTICS
Due to the proximity of the Chicago area there has
been a dramatic growth in the number of second
homes, along with the recent increases in tourism
and recreational related activities and shifts in |
employment trends in the southern and central
regions
of JoDaviess County, which have all contributed to
a doubling of traffic on US Route 20 over the past
two decades. Local commuting patterns and increased
truck travel have also contributed to the additional
traffic on US Route 20. In addition to the
significantly increased travel due to the tourist
attractions and developments, there are more local
trips and greater truck transport demands. |
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SYSTEM CAPACITY
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Existing traffic and traffic projections for
existing US Route 20 for the year 2020 indicate the
need for a four-lane facility. Current IDOT criteria
state that a four-lane facility is warranted when
traffic reaches a two-way Design Hourly Volume (DHV)
of 800. Presently this section of existing US Route
20 generally exceeds this with traffic volumes
ranging from 780 to 1100 DHV. |
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SAFETY CONCERNS
US Route 20 in the project area was
constructed through a land corridor whose
topographic and geologic features are
characterized by undulating terrain, with steep
ridges and narrow valleys and bedrock strata
that lie close to the surface. These physical
conditions directly influenced the highway’s
alignment configuration which often followed
existing contours of the area's ridges and
valleys.
The existing geometry of US Route 20 also
reduces the efficiency to move people and goods
through the region. Traffic backups develop at
many locations behind slow moving vehicles, a
result of extensive
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lengths of no-passing zones,
restricted sight distances, steep grades and,
generally, only one travel lane operating in each
direction. Most of existing US Route 20 between
Galena and Freeport does not meet IDOT’s current
design standards for rural highways. Nearly 50
percent of existing US Route 20 comprises vertical
and horizontal curves that do not meet IDOT’s
current standards for rural highways. In addition,
more than 10 percent of this section has grades
steeper than the maximum grade allowed for a roadway
to remain in place. |
| According to current
IDOT design standards for a two-lane roadway,
passing sight distance (passing zones) should be
available for at least 40 percent of a roadway’s
length. Passing zones account for about 35 percent
of the roadway. Actual passing opportunities are
available much less than this percentage due to the
high volume of traffic. |
From an operational perspective, US Route 20’s
history of relatively high accident rates is indicative
of substandard roadway geometry. Although many of the
accidents along US Route 20 may be attributable to
geometric deficiencies, straightening the curves and
widening the shoulders will not correct all the safety
problems along this section of US Route 20.
SYSTEM CONTINUITY
The IDOT Office of Planning and Programming
classifies US Route 20 as a Major Arterial Highway
within the rural State highway system. In general, this
means the route connects large towns or cities,
“long-distance trip” traffic generators, and integrates
interstate and intercounty services, while providing a
high degree of mobility at high operating speeds and
direct routing for long trips.
The proposed project is needed to
complete the missing four-lane section on US Route 20
between Illinois Route 84 northwest of Galena and the
Freeport Bypass. Upon completion of this project and the
Mississippi Bridge at Dubuque, US Route 20 would have
continuous four-lane capacity through northwestern
Illinois and northern Iowa from Rockford to Waterloo.
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