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Purpose
and Need
Excerpted from the 2003 Amended Scoping Document
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A. INTRODUCTION
Departments
of Transportation are responsible for providing mobility in a safe,
reliable and cost-efficient manner and for integrating environmental,
cultural, economic, and social considerations into transportation
solutions. While this integration is always a necessary part of
the DOTs' work, it is of particular importance and sensitivity as
the DOTs in Wisconsin and Minnesota contemplate improving mobility
and safety between the two states in the area of the existing crossing
between Washington County, Minnesota and St. Croix County, Wisconsin.
The goal is
to manage congestion and improve mobility in a reliable, safe and
cost-efficient manner as part of a broader program of regional transportation
improvements while avoiding (and when unavoidable, minimizing and
mitigating for) impacts to the area's social, economic, cultural
and environmental needs and objectives. A detailed discussion of
the purpose of and need for the project is presented in Appendix
C.
Underlying Transportation
Problem: Impaired mobility and safety concerns in the TH 36/STH
64 corridor between TH 5 in Minnesota and 150th Avenue in St. Croix
County, Wisconsin.
B. TRANSPORTATION
MOBILITY
- The 2002 Average
Annual Daily Traffic (AADT) volumes on the river crossing are
16,300 vehicles per day and can exceed 19,000 on a summer weekday. In 2008, the AADT was at 18,400 vehicles per day. The estimated (congestion-free) vehicle capacity for the current river crossing and arterial approaches is 11,200 vehicles a day. This constraint leads to periodic daily vehicular congestion in downtown Stillwater and on the Wisconsin approach to the bridge.
- The current Metropolitan Council/Mn/DOT travel
demand model forecasts average daily vehicle traffic on the
river crossing of 23,100 at an average vehicle occupancy of 1.30
persons per vehicle by the year 2030 if no new St. Croix River
crossing is built, no cross-river modal alternatives are established,
and Minnesota and Wisconsin projected development and programmed
roadway improvements occur as planned. This predicted increase
in vehicular traffic volume, if realized, will degrade traffic
operations and safety in downtown Stillwater, on the river crossing
and arterial approaches, and will increase average delay, queue
lengths and daily hours of congestion by 50 percent by the year
2030.
- Analysis
of existing signalized intersections in downtown Stillwater indicates
approximately 120-130 seconds of average delay per vehicle during
peak hour and levels
of service (LOS) D-F in 1999. These delays are affected by
close intersection spacing, restricted geometrics and delays due
to the bridge raising. For a regular peak hour commuter, this
delay results in 16 hours in total delay over the course of a
year.
- Geometric
and physical restrictions in downtown Stillwater limit the opportunities
to improve transportation operations and management.
- The river
crossing is susceptible to closures due to flooding, maintenance
activities and vehicle incidents that disrupt system connections
several times per year.
SAFETY
Crash rates
on two segments (one in Minnesota and one in Wisconsin) exceed the
statewide averages. The severity
rate for one segment in Minnesota is nearly double the statewide
average. The non-fatal injury crash rate for the Wisconsin segment
is 60 percent greater than the statewide average.
C. ENVIRONMENTAL,
CULTURAL, ECONOMIC AND SOCIAL CONSIDERATIONS
- The area
where transportation mobility and safety improvements are contemplated
includes the Lower St. Croix National Scenic Riverway (the Riverway);
therefore, it is necessary to protect the Riverway's Outstandingly
Remarkable Values -- scenic, recreational, and geologic -- as
guided by the Cooperative Management Plan for the lower St. Croix
National Scenic Riverway.
- It is necessary
to avoid and, if unavoidable, to minimize impacts to the Riverway's
channel, shoreline, bluffs, air quality and water quality.
- It is important
to respect the cultural value and historic significance of the
Stillwater Lift Bridge, a structure that is listed on the National
Register of Historic Places.
- It is important
to respect the integrity of the Stillwater Commercial Historic
District and the Stillwater Cultural Landscape District: The visual/aesthetic
quality, economic viability and physical integrity of these districts
are critical to the preservation of these resources and to the
protection of the cultural landscape and the community character.
- It is necessary
to avoid, and if unavoidable, to minimize impacts to area parklands,
cultural resources, threatened and endangered species and wetlands,
and if impacted, provide mitigation/compensation for the adverse
impacts.
- It is necessary
to examine the interaction of land use and transportation, and
consider the secondary and cumulative impacts of alternative methods
of addressing the transportation needs (and the full impact of
failing to address the transportation needs) expressed above.
- It is necessary
to avoid and, if unavoidable, minimize impacts to business and
property owners, residents and visitors throughout the project
area.
1 Level of service (LOS) is an indicator of intersection
operations as measured in average delay per vehicle. Six LOSs
are defined by facility type with the letters A-F designating
each level, with LOS A representing the best operating conditions,
and LOS F the worst. Each LOS represents a range of operating
conditions and the drivers' perception of those conditions. BACK
TO TEXT
2 Severity rate is a weighted average taking into account
fatal crashes, personal injury crashes, and property damage crashes. BACK
TO TEXT
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