HomeMy WebLinkAbout01-467 ATT.docTO:
FROM:
DATE:
RE:
MEMORANDUM
Richard Wollangk, City Manager
Mark Huddleston, Transportation Director
November 20, 2001
Q/HKO/H
ON THE WATER
Items Defeated by the Traffic Review Board at their November 13, 2001 Meeting
1)
REQUEST FOR A LEFT-TURN ARROW FOR WESTBOUND TRAFFIC ON 20TM AVENUE AT KNAPP
STREET. [EXISTING CONDITION: NO TURN ARROW].
This is a request from a Boardmember.
The standard warrant for a separate left turn phase is shown below:
1) If the left turn volume is less than 120 vph, no separate left turn phase is required.
2) If the left turn volume is between 120 vph and 240 vph, a left turn phase may
be required.
3) If the left turn phase is greater than 240 vph, a separate left turn phase is
recommended.
The above standards must be met for at least two hours per day.
20TH AVENUE AND KNAPP STREET
CITY TRAFFIC COUNTS 2001
HIGHEST TWO HOUR AVERAGE LEFT TURNS
Left-Turns Per Hour Left-Turns Per Cycle
Eastbound 59 1.3
When left turn volumes exceed 120 vehicles per hour, the opposing traffic needs to be considered. The following
calculation was made for the highest two hours of left turns.
20TH AVENUE AND KNAPP STREET
LEFT TURNS PER HOUR
Time Period Left Turns Opposing Traffic
Highest Two Hours 59 x 677 (.55) = 21,969
An intersection should be considered for a left turn arrow when the product of the left turns and the opposing t~-a221c exceeds
50,000 vehicles.
There were 9 accidents at 20th Avenue and Knapp Street during calendar year 2000. The westbound left turn movement
accounted for 4 accidents. I don't believe this number of left turn accidents justifies a left turn arrow at this time. I will
review this intersection at the end of 2001 to verify the number of left turn accidents at this intersection.
DEFEATED BY TRAFFIC REVIEW BOARD (0-5)