HomeMy WebLinkAboutCOUNCIL - AGENDA ITEM - 09/04/2001 - RESOLUTION 2001-120 ESTABLISHING CRITERIA FOR ARTE AGENDA ITEM SUMMARY ITEM NUMBER: 37
DATE: September 4, 2001
FORT COLLINS CITY COUNCIL FROM: Eric Bracke
SUBJECT:
Resolution 2001-120 Establishing Criteria for Arterial Intersection Analysis.
RECOMMENDATION:
Staff recommends adoption of the Resolution.
EXECUTIVE SUMMARY:
Several Councilmembers have inquired about the criteria that the City will use in determining the
placement of modern roundabouts. The modern roundabout has been used for years in other
countries as a safe and efficient form of intersection traffic control. The modern roundabout
design is now becoming increasingly popular with communities throughout the United States.
The increasing use of roundabouts in the U.S. is a result of studies and findings that roundabouts
are safer and more efficient intersections than the traditional traffic signal operation. It has also
been found that the public, although generally against the first roundabout in their communities,
become favorable to them in a very short period of time.
However, the modem roundabout design is not always the best solution to assigning right-of-way
at an intersection. A thorough analysis must be completed by a professional engineer trained
in traffic engineering. The Resolution outlines the process the Transportation staff is proposing
to use for future intersection improvement analysis.
Staff is proposing that when an intersection(arterial/arterial and arterial/collector intersections) is
sated or programmed for major improvements, whether by the City or development related, an
analysis shall be completed that evaluates traditional intersection design and a modern
roundabout. This alternatives analysis study will examine the two intersection types using the
following six criteria(in priority order):
1. Accident Analysis: A short-term accident analysis will be completed comparing the
safety aspects of the roundabout to the traditional intersection. The costs of accidents
as well as the type of accidents occurring will be evaluated. The costs associated
with the accidents will be based on data provided through the National Institute for
Insurance Safety.
2. Average Delay: The City currently has Level of Service (LOS) standards for both
signalized and unsignalized intersections. LOS is based on the average delay per
vehicle during the peak hours of the roadway. The analysis will make a comparison
of the current and projected(20 year) delay at the intersection.
DATE: September 4, 2001 2 ITEM NUMBER: 37
3. Environmental factors: The analysis will include an evaluation of the emissions at an
intersection under both scenarios. The analysis will include the emissions of carbon
monoxide, hydrocarbons, and oxides of nitrogen. The analysis will include other
factors such as impacts to existing trees and vegetation, wetlands, and noise impacts.
4. Cost: This section of the alternative analysis will include capital costs as well as long-
term maintenance and operation costs.
5. Alternative Mode Mobility: The study will include an evaluation of pedestrian and
bicycle mobility
6. Spatial Requirements: The amount of land area needed for each type of intersection
will be evaluated. Roundabouts generally, but not always, require more land area at
an intersection than a traditional intersection. However, the roundabout may provide
more than enough capacity to postpone or eliminate the need for roadway widening
between intersections.
On July 18, 2001, the Transportation Board reviewed the Resolution and criteria and
unanimously voted to recommend approval to the City Council. The Transportation Board was
also very enthusiastic regarding the need and potential for modern roundabouts within the city.
The Board views the roundabout alternative as a cost effective way of improving traffic flow and
traffic safety.
Attached is correspondence from city residents regarding the Intersection Analysis Resolution.
RESOLUTION 2001-120
OF THE COUNCIL OF THE CITY OF FORT COLLINS
ESTABLISHING CRITERIA FOR
ARTERIAL INTERSECTION ANALYSIS
WHEREAS, some cities and states across the country have begun to construct
roundabouts at roadway intersections in place of traffic signals and auxiliary lanes; and
WHEREAS, the modern roundabout can be a safer and more efficient intersection than an
intersection controlled by traffic signals; and
WHEREAS, roundabout construction may have cost savings in both the short term
capital costs and long term operation and maintenance costs.
NOW, THEREFORE, BE IT RESOLVED BY THE COUNCIL OF THE CITY OF
FORT COLLINS as follows:
Section 1. That the City Council hereby determines for any major planned roadway
improvement (other than maintenance projects and improvements funded through the Pavement
Management Program) which involves an arterial/arterial or an arterial/collector intersection, an
Intersection Alternative Analysis will be conducted to assist the Transportation staff in
determining the most appropriate improvements for the intersection in question.
Section 2. That each Intersection Alternative Analysis shall include the following
evaluations of standard intersection improvements and roundabout improvements:
• Accident Analysis — a short-term accident analysis shall be conducted for
each of the alternatives analyzed. Costs associated with accidents will be
based on data provided through the National Institute for Insurance Safety.
• Average delay — the morning, noon, and afternoon peak hours shall be
compared and analyzed through capacity analyses to determine the average
vehicle delay for each leg of the intersection. The capacity analysis shall
include 20-year traffic projections.
• Environmental Factors—an air quality comparison between a roundabout and
signalized intersection shall be included in the report.
• Cost — capital costs as well as long-term maintenance and operation costs
shall be included in the study.
• Alternative Mode Mobility — the study shall include an evaluation of
pedestrian and bicycle mobility.
• Spatial Requirements — the study shall evaluate the amount of land area
needed for each type of intersection and the costs associated with the
acquisition of the same.
Passed and adopted at a regular meeting of the Council of the City of Fort Collins held
this 4th day of September, A.D. 2001.
Mayor
ATTEST:
City Clerk
We have some comments on the draft resolution Establishing Criteria for
Modem Roundabout Construction on Public Arterial Roadways.
There should be a bullet point in Section 2 that addresses the"Impact on
Private Property"used to construct each intersection alternative,as well
as other private property in the vicinity.The "Spatial Requirements" bullet
point implies that a modem roundabout will have greater impact on private
property,which may be the case at many intersections.
The opposite is the case at the Harmony-Shields intersection.Our property
is 500*x 500*and has access points on Harmony and Shields located about
200*from the intersection. If a signalized intersection is constructed,new
access points will need to be constructed on Harmony and Shields about 470*
from the intersection.This will destroy our backyard and leaves us with
driveways that lead to the rear rather than the front of our home.
The"Impact on Private Property"section should also weight the costs and
benefits of constructing additional roundabout arms to provide access points
to affected private property.I support a 5 arm roundabout that includes an
arm for access to our property,but we oppose a 4 arm roundabout that does
not provide me with access.The fifth arm requires additional diameter for
the roundabout and increases the cost,which we are willing to bear.
A major advantage of a roundabout is the reduction in noise pollution,due
to the slower speeds.This may not be a factor in some intersections where
there are few residential uses nearby,but other locations will have heavy
residential uses. This needs to be addressed in an "Impact on Private
Property"analysis. In the case of Harmony-Shields,the Woodlands apartment
complex and the Westbury subdivision would benefit greatly from the
diminished noise of a modem roundabout.
The"Environmental Factors"bullet point should also require comments from
the City Forrester pertaining to landscaping. In the Harmony-Shields case,
the road widening will require the City to relocate 8 Colorado Blue Spruce
trees, each of which are 30*40*tall. If the highest quality of these trees
are transplanted to the Central Island of a modem roundabout,a landmark
intersection will be created with superior landscaping relative to a
signalized intersection,as well as the Vail Village roundabout that started
the roundabout movement. A signalized intersection requires moving the trees
further away,which increases the probability of an unsuccessful transplant.
If similar opportunities are available at other intersections,this should
be discussed in the"Environmental Factors"analysis.
Mary and Mark Brophy