HomeMy WebLinkAboutAgenda Report - July 17, 1996 (75)AGENDA TITLE: Traffic Resolution Amendment - Speed Limit Survey on Ham Lane
MEETING DATE: July 17, 1996
PREPARED BY: Public Works Director
RECOMMENDED ACTION: That the City Council adopt a resolution amending the Traffic Resolution
#87-163 by approving the speed limit change from 35 to 40 miles per
hour on Ham Lane between Lodi Avenue and Vine Street.
BACKGROUND INFORMATION: The Public Works Department recently performed Engineering and
Traffic Surveys on nine City streets. Per Section 40802(b) of the
California Vehicle Code, Engineering and Traffic Surveys must be
updated within a minimum of every five years on "non -local" streets.
Speeds on streets on which surveys exceed five years cannot be enforced using radar. "Non -local"
streets are collector and arterial streets on the Federal Aid System.
Attached as Exhibit A are the results of the nine surveys performed. As indicated, speed limit
modifications are recommended on the portion of Ham Lane between Lodi Avenue and Vine Street.
The survey is attached as Exhibit B.
The surveys performed, which follow State of California Department of Transportation guidelines,
include maps and written narratives for each street. The maps show physical characteristics and field
data, such as roadway widths, number of through lanes, traffic controls, traffic volumes, prevailing
speeds, and accident rates. Accident rates are determined by the number of accidents occurring within
a segment of roadway and the traffic volume within that segment. Accident rates are shown in
accidents per million vehicle miles (ACC/MVM). The average citywide accident rate is 4.4 ACC/MVM.
The narratives describe the data indicated in the maps and results of the survey.
Three factors should be considered in determining the speed limit most appropriate to facilitate the
orderly and reasonably safe movement of traffic. These factors are prevailing speeds, unexpected
conditions to drivers, and accident records. Reasonable speed limits conform to the actual behavior of
the majority of motorists and, by measuring motorists' speeds, one will be able to select a speed limit
both reasonable and effective. Speed limits should normally be established at the first five mile per
hour (mph) increment below the 85th percentile speed. However, in matching existing conditions with
the traffic safety needs of the community, engineering judgment may indicate the need for a further
reduction of five mph.
APPROVED: �.
H. Dixon Flynn -- City anger
CSPLMHAM.DOC 07/08/96
Traffic Resolution Amendment - Speed Limit Survey on Ham Lane
July 17, 1996
Page 2
SURVEY RESULTS
A speed limit change is recommended on the following portion of Ham Lane:
Vine Street to Lodi Avenue - Vehicle speeds recorded in this segment support a 40 mph speed limit.
The accident rate of 2.5 is significantly below the citywide average. Based on the increase in prevailing
speeds and low accident rate, we recommend increasing the speed limit on this segment from 35 mph
to 40 mph.
RECOMMENDATION
Staff recommends the following speed limit change on Ham Lane:
SEGMENT
SPEED LIMIT
Vine Street to Lodi Avenue 35 to 40 mph
FUNDING: Funding to modify speed limit signs and legends from the
Street Maintenance Account at an approximate cost of $450.
Jack L. Ronsko V
Public Works Director
Prepared by Rick S. Kiriu, Senior Engineering Technician
JLR/RSK/Im
Attachments
cc: City Attorney
Police Chief
City Engineer
Street Superintendent
Associate Traffic Engineer
CSPLMHAM.DOC 718196
Recommended Speed Limit Changes
The recommended speed limit changes are shown in bold and italics.
1. Brandywine Drive
6. Lockeford Street
Ham to Hutchins
35 mph (no change)
Mills to Ham
Ham to California
2. California Street
California to Church
Lockeford to Turner
30 mph (no change)
Church to Stockton
Stockton to Cherokee
3. Eilers Lane
Cherokee to E. City Limits
Woodhaven to Lilac
30 mph (no change)
Lilac to Lower Sac
30 mph (no change)
7. Loma Drive
Elm to Lockeford
4. Ham Lane
Lockeford to Turner
Harney to Century
35 mph (no change)
Century to Kettleman
40 mph (no change)
8. Sacramento Street
Kettleman to Vine
40 mph (no change)
Lockeford to Turner
Wine to Lodi
35 to 40 mph
Lodi to Lockeford
35 mph (no change)
9. Stockton Street
Lockeford to Turner
35 mph (no change)
Harney to Kettleman
Kettleman to Tokay
5. Kettleman Lane
Tokay to Lockeford
Highway 99 to Beckman
35 mph (no change)
Lockeford to Turner
Beckman to E. City Limits
40 mph (no change)
96CHANGI .XLS
EXHIBIT A
Date: July 8, 1996
35 mph (no change)
35 mph (no change)
35 mph (no change)
30 mph (no change)
35 mph (no change)
35 mph (no change)
30 mph (no change)
35 mph (no change)
35 mph (no change)
45 mph (no change)
35 mph (no change)
35 mph (no change)
35 mph (no change)
ENGINEERING
AND -TRAFFIC SURVEY m z
SEE NARRATIVE FOR ~" > o
7 W N < Q Y O W
BACKGROUND INFORMATION a Y1300' n w� EDGEw00D DR
z a rc 1100'
T 'I R' 2soo 2650
> q '� 2200• R
R,//
L
F 2750' F h F 3 M F 1300' F I F 900' F R, r
1300'
1/2 MILE I 1/2 MILE I 1/2 MILE l 1/2 MILE I.. 1/2 MILE I 1/2 MILE
SPEED TABLE
ROADWAY WIDTH H 64'-84' VARIES -- 64' -I- 55' VARIES -f- 60 -1- 56'-62' -1
--- - -- --
NO. OF LANES I F_ — 4 _ _ + 2 + LT LANE -f- 4 -{
MEDIAN (TYPE) NONE
TRAFFIC SIGNAL DATA 80ACT 20ACT 20ACT 80ACT 60ACT 20ACT _ 20ACT
AVERAGE DAILY TRAFFIC 6800 8900 (911D)9320 17500 16400 15800 15220 13000 10490 (9700) 7650
-
OBS. SPEED-CRITICAL,85th% SB, 41 44 41 40 38 40
39 _ 42 41 40 37 _ 39
PACE % SBi 32-42 (80) 34-44 82
- e ( )-- 33-43 (88) 32742 (77) 30-40 (81) - 31-41 (77)
NB 30-40 (80) _ 33-43 (84) 33-43 (85) - 31-41 (83) 29-39 (88) 30-40 (81)
-MEDIAN,50th% SB; 36 39 37 36 34 35
------------- — ----- - --- -----
NBI 35 38 37 _ 35 34 35.
EXISTING SPEED ZONE F- 35 MPH -F- 40 MPH -I- 35 MPH -1
PROPOSED SPEED ZONE! f- 35 MPH -I- 40 MPH -I- 35 MPH -{
LEGEND: MPH SPEED GRAPH
—(-;
T -SIGN LOCATION L. —._ — I _7--T-
Rl -STOP SIGN
R2() SPEED LIMIT SIGN (NPH) 1 50- 1
-
R1-2 YIELD SIGN �. 1 1---74
C -INSTALLATION
(SCHOOL 25 MPH
SIGNS.(N'BS.R2(2S). 40 I - ' �--
+- �ISff_
-TRAFFIC SIGNAL
-CITY LIMIT 30I
CRRICAL SPEED .-.
-LONER LINK OF PACE �, '_. _• -- ..•^ t - -_ T � -�
ACCIDENT PLOT YR: 19941 1 1 1 1 1 2 2 3 3 1 2 1 2 1 1 2 2 1 1 2 1 1 1 1 31 1 2 1 1
YR; 1995'1 .,. ..1 —1 1 2 1 1 4 3 1 1 111 1 1 3 4 1 1 31 1 1 1
ACCIDENT RATE-ACC./MILL. VEH.-MI. 1.9 3.7 2.5 1 2.4 1 2.5 3.5 1 6.2 1 2.1
'R RR No. DoteRevision Pr ApOrewe By
CITY OF LO D I SPEED
' - ----- - HAM LN ZONE
MTE Cfty EPq�neer Dote
JUNE 1996 — -- """--- Rti No 2A,AD PUBLIC WORKS DEPARTMENT SURVEY
July 1996
SPEED ZONE REPORT - Ham Lane
° REFERENCE - Speed zone surveys are performed in the City of Lodi following
State of California Department of Transportation (Caltrans) guidelines in
accordance with Section 40802 (b) of the California Vehicle Code. These
guidelines are outlined in Chapter 8 of the Caltrans Traffic Manual.
° STUDY
Important factors to consider in determining the speed limit which is most
appropriate to facilitate the orderly movement of traffic and that is reasonably safe
are prevailing speeds, unexpected conditions to drivers, and accident records.
Prevailing Speeds (85th Percentile Speeds) - Reasonable speed limits conform to
the actual behavior of the majority of motorists, and by measuring motorists'
speeds, one will be able to select a speed limit that is both reasonable and
effective. Speed limits should normally be established at the first five mile per hour
increment below the 85th percentile speed. However, in matching existing
conditions with the traffic safety needs of the community, engineering judgment
may indicate the need for a further reduction of five miles per hour.
Twelve radar surveys were performed and the 85th percentile speeds ranged from
37 to 44 mph as shown below:
Street Segment
Northbound Southbound
Harney Lane to Century Boulevard
39 mph
41 mph
Century Boulevard to Kettleman Lane
42 mph
44 mph
Kettleman Lane to Vine Street
41 mph
41 mph
Vine Street to Lodi Avenue
40 mph
40 mph
Lodi Avenue to Elm Street
37 mph
38 mph
Elm Street to Turner Road
39 mph
40 mph
Unexpected Conditions
When roadside development results in traffic conflicts and unusual conditions which
are not readily apparent to drivers, speed limits below the 85th percentile are
warranted. The following factors were considered: roadway design speed, safe
stopping sight distance, superelevation, shoulder conditions, profile condition,
intersection spacing and offsets, commercial driveway characteristics, and
pedestrian traffic in the roadway without sidewalks.
Accidents
Accident records of the two most recent years were considered in determining the
speed zones. Accidents on segments of roadways are classified by their accident
rate. Accident rates are determined by the number of accidents occurring within a
segment of roadway and the traffic volume within that segment. Accident rates are
HAMSP.DOC
SPEED ZONE REPORT - Ham Lane
Page 2
shown in accidents per million vehicle miles (ACC/MVM). The accident rate ranged
from 1.9 to 6.2 ACC/MVM. The average Citywide accident rate is 4.4 ACC/MVM.
° CONCLUSION
Hamev Lane to Century Boulevard
The 85th percentile speeds on this segment are 39 and 41 mph. The 50th
percentile speeds are 35 and 36 mph. The accident rate of 1.9 in this segment is
lower than the Citywide average and has not changed from the 1991 survey.
Based on the prevailing speeds and continuing low accident rate, we recommend
retaining the 35 mph speed limit in this segment.
Century Boulevard to Kettleman Lane
The 85th percentile speeds on this segment are 42 and 44 mph. The 50th
percentile speeds are 38 and 39 mph. The accident rate of 3.7 is lower than the
Citywide average and slightly higher than the 2.8 rate from the 1991 survey. Based
on prevailing speeds and low accident rate, we recommend retaining the 40 mph
speed limit in this segment.
Kettleman Lane to Vine Street
The 85th percentile speed on this segment is 41 mph. The 50th percentile speed is
37 mph. The accident rate of 2.5 is lower than the Citywide average and slightly
higher than the 2.0 rate from the 1991 survey. Based on prevailing speeds and low
accident rate, we recommend retaining the 40 mph speed limit in this segment.
Vine Street to Lodi Avenue
The 85th percentile speed on this segment is 40 mph. The 50th percentile speeds
are 35 and 36 mph. The highest accident rate of 2.5 in this segment is below the
Citywide average and lower than the 4.0 rate from the 1991 survey. Based on the
increase in prevailing speeds and continuing low accident rate, we recommend
increasing the speed limit in this segment from 35 to 40 mph.
Lodi Avenue to Lockeford Street
The 85th percentile speeds on this segment are 37 and 38 mph. The 50th
percentile speed is 34 mph. The highest accident rate of 6.2 is above the Citywide
average and slightly lower than the 6.3 rate from the 1991 survey. Although the
accident rate is above the Citywide average, the amount is not significant. Based
on prevailing speeds and reasonable accident rate, we recommend retaining the
35 mph speed limit on this segment.
W,,Ki.
SPEED ZONE REPORT - Ham Lane
Page 3
Lockeford Street to Turner Road
The 85th percentile speeds on this segment are 39 and 40 mph. The 50th
percentile speed is 35 mph. The accident rate of 2.1 in this segment is below the
Citywide average and lower than the 5.0 rate from the 1991 survey. Based on
prevailing speeds and reduced accident rate, we recommend retaining the speed
limit 35 mph in this segment.
The recommended speed limits are shown below:
STREET SEGMENT
Harney Lane to Century Boulevard
Century Boulevard to Kettleman Lane
Kettleman Lane to Vine Street
Vine Street to Lodi Avenue
Lodi Avenue to Lockeford Street
Lockeford Street to Turner Road
Richard C. Prima, Jr.
City Engineer
HAMSP.DCC
POSTED SPEED LIMIT
35 mph (no change)
40 mph (no change)
40 mph (no change)
35 to 40 mph
35 mph (no change)
35 mph (no change)
RESOLUTION NO. 96-97
A RESOLUTION OF THE LODI CITY COUNCIL
APPROVING SPEED LIMIT CHANGE ON HAM LANE BETWEEN
LODI AVENUE AND VINE STREET, AND THEREBY AMENDING
TRAFFIC RESOLUTION NO. 87-163
WHEREAS, speed zone surveys are performed in the City of Lodi following State of
California Department of Transportation (Caltrans) guidelines in accordance with Section
40802(b) of the California Vehicle Code, which are outlined in Chapter 8 of the Caltrans Traffic
Manual.
RESOLVED, that the City Council of the City of Lodi does hereby approve the speed limit
change on Ham Lane between Lodi Avenue and Vine Street from 35 to 40 miles per hour; and
FURTHER RESOLVED, that City of Lodi Traffic Resolution No. 87-163, Section 7
"Speed Limits" is hereby amended by designating a speed limit change on Ham Lane between
Lodi Avenue and Vine Street from 35 to 40 miles per hour.
Dated: July 17, 1996
I hereby certify that Resolution No. 96-97 was passed and adopted by the City Council of
the City of Lodi in a regular meeting held July 17, 1996, by the following vote:
AYES: COUNCIL MEMBERS - Davenport, Mann, Pennino, Sieglock
and Warner (Mayor)
NOES: COUNCIL MEMBERS - None
ABSENT: COUNCIL MEMBERS - None
ABSTAIN: COUNCIL MEMBERS - None
JIFER PERRIN
G y Clerk
96-97