Barstow City Council
July 1, 2024

CITY OF BARSTOW

ENGINEERING AND TRAFFIC SURVEYS FOR

SPEED LIMITS
DECEMBER 2021
Prepared for:

City of Barstow
220 E. Mountain View Street, Suite A
Barstow, CA 92311
Prepared By:
2141 W. Orangewood Avenue
Orange, CA 92868
T: 714.573.0317 | F: 714.573.9584
www.koacorp.com
JB93128
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE I 2141 W. Orangewood Avenue, Orange, CA 92868
T: 714.573.0317 | F: 714.573.9534 | www.koacorp.com

MONTEREY PARK ORANGE ONTARIO SAN DIEGO
December 23, 2021
Mr. Domingo D. Gonzalez
Engineering Services Administrator / Project Manager
City of Barstow
220 E. Mountain View Street, Suite A
Barstow, CA 92311
Subject: Citywide Engineering and Traffic Surveys for Speed Limits Dear Mr. Gonzalez,
KOA Corporation presents this Citywide Engineering and Traffic Survey (E&TS) report to justify and update the posted speed limits along 57 street segments in the City of Barstow.

The enclosed report describes the methodology and contains the recommendations for the posted speed limits on the City’s roadway system. This report provides a summary of these recommendations.

Supporting documentation for each speed zone recommendation is provided in the Appendices.

The survey was conducted in accordance with the applicable provisions of the CVC, following procedures outlined in the latest California Manual on Uniform Traffic Control Devices, as required by Section 627 of the CVC. This report is intended to satisfy the requirements of Section 40802 of the CVC to enable the continued use of radar or other electronic devices for traffic speed enforcement.

Sincerely,
Walter Okitsu, PE, PTOE, PTP, RSP21
Vice President | Principal
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE II

TABLE OF CONTENTS

1.0 EXECUTIVE SUMMARY AND BACKGROUND ....................................................................... 1 Executive Summary .................................................................................................................................................................... 1 Project Background ................................................................................................................................................................... 1

2.0 METHODOLOGY ........................................................................................................................ 12 Data Collection ......................................................................................................................................................................... 12 Collision Analysis ..................................................................................................................................................................... 12 Land use and Attractors ........................................................................................................................................................ 13 Review Criteria .......................................................................................................................................................................... 17

3.0 RESULTS AND RECOMMENDATIONS ................................................................................. 19 Recommendations .................................................................................................................................................................. 19 Speed Limit Changes ............................................................................................................................................................. 19

4.0 CERTIFICATION ........................................................................................................................ 22

LIST OF FIGURES
Figure 1.1 – Speed Survey Locations Map – East/Downtown Barstow ........................................................................... 5 Figure 1.2 – Speed Survey Locations Map – West Barstow ................................................................................................. 6 Figure 1.3 – Traffic Count Locations Map – East/Downtown Barstow ............................................................................ 7 Figure 1.4 – Traffic Count Locations Map – West Barstow .................................................................................................. 8 Figure 1.5 – Existing posted speed limits ................................................................................................................................. 11 Figure 1.6 – Citywide Collisions on study segments (2018-2020) ................................................................................. 14 Figure 1.7 – Citywide Land Use and Select Attractors – East/Downtown Barstow .................................................. 15 Figure 1.8 – Citywide Land Use and Select Attractors – West Barstow ........................................................................ 16 Figure 3.1 – Recommended Speed Limits ............................................................................................................................... 21

LIST OF TABLES
Table 1.1 – Speed Survey Summary Table .................................................................................................................................. 2 Table 1.2 – Traffic Count Summary Table ................................................................................................................................... 9

APPENDIX
Appendix A – Engineering and Traffic Survey Forms for Each Segment Appendix B – Average Daily Traffic (ADT) Count Data
Appendix C – Speed Zone Survey Data
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 1

1.0 INTRODUCTION AND BACKGROUND

INTRODUCTION
Through the course of completing the 2021 Citywide Engineering and Traffic Survey (E&TS) for Speed Limits report, speed surveys were collected at 57 locations and Average Daily Traffic (ADT) counts were collected along 60 segments. Figure 1.1, Figure 1.2, and Table 1.1 illustrate the locations of the data collection and the existing conditions.

The recommendations contained in this report are based on the speed and traffic count data that was collected and is intended to be used to establish or justify posted speed limits that can be enforced by radar. Recommended speed limits have been determined in accordance with the procedures set forth in the latest California Manual of Uniform Traffic Control Devices (CA MUTCD) and Assembly Bill 43 (AB-43), and are based on prevailing speeds as demonstrated by field survey. AB-43 was approved by the Governor of California on October 8, 2021 with an effective date of January 1, 2022. Table 1.1 summarizes the findings and recommendations of this report, and the changes in speed limit are highlighted in bold text.

PROJECT BACKGROUND
The 2021 Citywide E&TS for speed limits report for the City of Barstow is required by California Vehicle Code (CVC) Sections 22357 and 22358, which mandate local agencies to follow procedures outlined by Caltrans in establishing speed limits or in updating speed zone surveys. The CVC requires speed zones to be evaluated on a recurring basis to assure that the posted limits are justified for roadway conditions.

Engineering studies should be conducted at least once every 5, 7, or 14 years, in compliance with CVC Section 40802. If the required surveys are more than 5, 7, or 14 years old, the court may reject the evidence of speeding obtained by use of radar under CVC Section 40802 and 627, and Section 2B.13 of the CA MUTCD.

The procedure is built around a "Spot Speed Survey" which normally consists of the measured speed of at least 100 vehicles. Based upon this survey, the speed limit is established or justified at the 5 mph interval that is nearest to the 85th percentile of free-flowing traffic recorded by the spot speed survey. The rounding procedure requires rounding to the nearest 5 mph. For example, an 85th percentile of 34 mph must be rounded to 35 mph. “However, in cases in which the speed limit needs to be rounded up to the nearest five miles per hour increment of the 85th-percentile speed, the Department of Transportation or a local authority may decide to instead round down the speed limit to the lower five miles per hour increment.

A local authority may additionally lower the speed limit as provided in Sections 22358.7 and 22358.8.” (AB43) These surveys are intended to be the basis for establishing, revising, and enforcing speed limits. Sections 40801 and 40802 of the CVC require Engineering and Traffic Surveys to support the posted speed limit before speed limits can be enforced with radar. The procedures for updating speed limits are outlined in the latest CA MUTCD. The California Vehicle Code (CVC) Section 627 lists various special circumstances that might justify a speed zone lower than the speeds indicated by the speed survey. These circumstances would include continuity of speed limit, high collision rate, unusual roadway geometry, sight distance issues, pedestrian activity, sensitive land uses such as schools, and other case-by-case factors.

Executive Summary and Background
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 2 Table 1.1 – Speed Survey Summary Table
ID Street From To Posted Speed Limit (mph) 85th Percentile Speed Rounded Up to Nearest 5 MPH Rounded Down to Nearest 5 MPH Collision Rate 2018-2020 (per MVM) Expected (3-year) Collision Rate (per MVM)1 Recommended Speed Limit (mph) Remarks /Justifications 1 Armory Road
Wisteria Avenue Barstow Road N/A 37.4 - 35 32.49 1.61 30 1A 2 Barstow Road Muriel Drive 45 48.3 50 - 3.97 1.34 45 6A 3 Muriel Drive Higgins Road 40 41 - 40 2.71 1.32 40 4 Higgins Road Montara Road 25 33 35 - 20.27 1.61 25 7A 5 Barstow Road
Virginia Way Mountain View Street 35 37.1 - 35 3.60 1.61 35 6 Mountain View Street E. Main Street 35 37.9 40 - 27.03 1.61 35 6A 7 Broadway Avenue Armory Road Rimrock Road 40 42.5 45 - 2.78 1.61 40 6A 8 E. Main Street
Barstow Road Seventh Avenue 35 36.7 - 35 5.29 1.34 35
9 Seventh Avenue Muriel Drive 35 37.8 40 - 1.37 1.34 35 6A 10 Muriel Drive Yucca Avenue 40 38.5 40 - 8.93 1.34 40 11 Yucca Avenue Coolwater Lane 40 43.2 45 - 20.88 1.34 40 6A 12 First Avenue Barstow Road 25 30.7 - 30 77.07 1.34 25 7A 13 First Avenue
Main Street Hutchinson Street 35 36.2 - 35 10.03 1.61 35 14 Hutchinson Street Riverside Drive 35 37.6 40 - 1.67 1.61 35 15 Riverside Drive Irwin Road 35 51.2 - 50 2.23 1.61 35 7A 16 Irwin Road Old Hwy 58 50 54.7 55 - 0.00 1.61 50 6A 17 Lenwood Road
I-15/Outlet Center Drive Mercantile Way 65 54.2 55 - 0.18 1.61 55 18 Mercantile Way High Point Parkway 35 35.2 - 35 4.32 1.34 35 19 1,500 feet north of Commerce Parkway W. Main Street 50 52.9 55 - 0.78 1.61 55 20 W. Main Street Jasper Road N/A 55.4 - 55 0.00 1.34 55 21 Montara Road
Rimrock Road Forane Street 40 43.1 45 - 0.70 1.34 40 3C, 4B 22 Forane Street Armory Road 40 43.5 45 - 2.00 1.34 40 1A, 3B, 3C, 4B 23 Armory Road I-40 40 42.1 - 40 12.91 1.34 40 24 Mountain View Street
Avenue A First Avenue 30 34.3 35 - 2.01 1.61 30 3C
25 First Avenue Barstow Road 30 36.8 - 35 4.04 1.32 30 1A, 3C 26 Barstow Road Seventh Avenue 25 37.9 40 - 4.74 1.61 35 1A, 3C 27 Seventh Street Lillian Drive 35 39.2 40 - 0.00 1.61 35 28 Lillian Drive Muriel Drive 35 38 40 - 8.69 1.61 35 29 Muriel Drive Yucca Avenue 35 37.4 - 35 20.92 1.61 35 30 Yucca Ave E. Main Street 35 36.7 - 35 2.84 1.61 35 31 Opal Ave Armory Road Rimrock Road 35 38.2 40 - 4.24 1.61 35 32 Rimrock Road
Agarita Ave H Street 50 53.7 55 - 1.76 1.61 50
33 Barstow Road Agarita Avenue 50 53.5 55 - 13.14 1.34 50 34 Princeton Drive Barstow Road 45 49 50 - 3.48 1.34 45 Executive Summary and Background
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 3 ID Street From To Posted Speed Limit (mph) 85th Percentile Speed Rounded Up to Nearest 5 MPH Rounded Down to Nearest 5 MPH Collision Rate 2018-2020 (per MVM) Expected (3-year) Collision Rate (per MVM)1 Recommended Speed Limit (mph) Remarks /Justifications 35 Rimrock Road
Princeton Drive Monterey Ave 45 49.2 50 - 1.88 1.34 45
36 Monterey Avenue Mesquite Drive 45 50.3 - 50 24.19 1.34 45 1A, 4B 37 Mesquite Drive Montara Road 45 50.5 - 50 0.24 1.34 45 3C, 4B 38 Roberta Street E. Main Street Virginia Way 35 36.3 - 35 36.42 1.61 35 39 W. Main Street
Western Drive Hwy 58 55 57.1 - 55 0.83 1.34 55
40 Hwy 58 Plaimor Avenue 55 57.1 - 55 1.33 1.34 55 41 Plaimor Avenue Laverne Avenue 55 57.2 - 55 2.07 1.34 55 42 Laverne Avenue L Street 45 45.3 - 45 8.10 1.34 45 43 L Street Avenue H 45 45.1 - 45 4.60 1.34 45 44 Avenue H Otis Avenue 40 43.7 45 - 11.23 1.34 40 6A 45 Otis Avenue First Avenue 35 37.5 40 - 11.11 1.34 35 6A 46 Avenue H W. Main Street I-15 50 49.4 50 - 5.01 1.61 50 47 Muriel Drive
Armory Road Rimrock Road 40 45.1 - 45 1.57 1.34 40 1A, 3C 48 Rimrock Road Guadalupe Drive N/A 45.1 - 45 0.68 1.34 40 4B 49 Virginia Way Armory Road 35 41.6 - 40 3.34 1.61 35 1A, 4B 50 Riverside Drive
First Avenue Railroad Track 25 34.2 35 - 0.00 1.61 35
51 Railroad Track Yucca Avenue 25 44.5 45 - 1.04 1.61 40 6A 52 Yucca Avenue
Riverside Drive E. Main Street 35 36.9 - 35 1.36 1.61 35 53 E. Main Street Mountain View Street 30 33.4 35 - 0.80 1.61 30 54 Virginia Way
Barstow Road Mayor Helen Runyon Drive 25 34.2 35 - 2.76 1.61 30 1A, 3C 55 Mayor Helen Runyon Drive Lillian Drive 25 35.3 - 35 3.84 1.61 30 1A, 2A, 3C 56 Higgins Road Armory Road Rimrock Road 35 33.5 35 - 0.31 1.61 35 57 L Street I-15 Main Street N/A 46.2 - 45 3.97 1.34 45 Note 1: 2018 Crash Data on California State Highways, Caltrans, 3-Year Crash Rates Highlighted and bold roadway segments in the table indicate a proposed speed limit that is either, lower, higher, or a new speed limit from the existing posted speed limit.

Remarks/Justification:
1A. Collision Records (may indicate traffic conflict or unusual conditions not readily apparent to the driver) (CVC 627(b)(2) & CVC 627(b)(3)) 2A. Residential Density (contiguous one-side frontage of 13 or more dwelling units in 1/4 mile) (CVC 627(c)(1)(A)) 2B. Residential Density (contiguous two-side frontage of 16 or more dwelling units in 1/4 mile) (CVC 627(c)(1)(B)) 2C. Residential Density (ratio of dwelling units or business structures described in 2A or 2B but with a total length over 1/4 mile) (CVC 627(c)(1)(C)) 3A. Pedestrian Activity (e.g., School Zones) - In Roadway Without Sidewalks (CVC 627(c)(2)) 3B. Pedestrian Activity (e.g., School Zones) - At Mid-block Crossings (CVC 627(c)(2)) 3C. Nearby Pedestrian Generators (such as schools, parks and senior housing facilities) (CVC 627(c)(2)) 4A. Safe Stopping Distance (visibility obstructions) 4B. Continuity (avoid speed zones less than 1/2 mile and short transition zones) 5A. Business Activity District (CVC 22358.9) 6A. 85th percentile speed rounded down (CVC 22358.6) 7A. Retain the current speed limit in accordance with CVC 22358.8(a) Executive Summary and Background
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 4 The CVC Section 40802 also provides an exemption to the required survey. Streets defined as a “local street or road” on California Road System Maps, which are approved by the Federal Highway Administration (FHWA) and maintained by the Department of Transportation, are not required to be surveyed. If maps have not been submitted, local streets or roads are defined as those streets providing primary access to abutting residential property and meeting the following three conditions:
 Roadway width of no more than 40 feet
 Not more than ½ mile of uninterrupted length (interruptions include stop signs or traffic signals)  Not more than one traffic lane in each direction
Roadway conditions for those street segments where the radar surveys suggested a speed limit change were evaluated and enumerated for those conditions outlined above, to determine the proper speed limit, as well as to assist the Court in understanding the reasons for reducing the speed limit below the rounded 85th percentile value.

The Engineering and Traffic Survey review was conducted in accordance with procedures outlined in the California MUTCD, Section 2B.13, using the short method of speed zoning applicable for “City and County Through-Highways, Arterials, Collector Roads and Local Streets.” The Engineering and Traffic Survey process was performed as required by Section 627 of the CVC. This section of the CVC specifies three considerations that must be included in Engineering and Traffic Surveys:
 Prevailing speeds as determined by traffic engineering measurements  Collision records
 Highway, traffic, and roadside conditions not readily apparent to the driver Furthermore, Section 627 of the CVC allows local authorities to consider the prevailing speeds, collision records, residential density, and pedestrian and bicyclist safety in determining speed limits.

Posted speed limits are primarily established to distinguish the general public from the unreasonable driver. Appropriate speed limits provide law enforcement with the means to identify and apprehend violators of the Basic Speed Law (Section 22350 of CVC). This statute states “No person shall drive a vehicle on a highway at a speed greater than is reasonable or prudent having due regard for weather, visibility, the traffic on, and the surface and width of the highway, and in no event at a speed which endanger the safety of persons or property”.

The fundamentals used to establish speed limits recognize that the majority of drivers behave in a safe and reasonable manner, but need to be advised of conditions which may not be readily apparent. For this reason, collision history, roadway conditions, traffic characteristics, and land use must be analyzed along with speed measurements to determine speed limits. Speed limit changes are usually coordinated with visible changes in roadway conditions or roadside developments. In general, short zones of less than one-half mile in length should be avoided.

Speed limits cannot be successfully enforced without voluntary compliance by a majority of drivers.

Consequently, only the driver whose behavior is clearly out of line with the normal flow of traffic is considered a violator for enforcement purposes.

Executive Summary and Background
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 5 FIGURE 1.1 – SPEED SURVEY LOCATIONS MAP – EAST/DOWNTOWN BARSTOW Executive Summary and Background
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 6 FIGURE 1.2 – SPEED SURVEY LOCATIONS MAP – WEST BARSTOW
Executive Summary and Background
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 7 FIGURE 1.3 – TRAFFIC COUNT LOCATIONS MAP – EAST/DOWNTOWN BARSTOW Executive Summary and Background
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 8 FIGURE 1.4 – TRAFFIC COUNT LOCATIONS MAP – WEST BARSTOW Executive Summary and Background
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 9 Table 1.2 – Traffic Count Summary Table
ID Street From To Average Daily Traffic
(ADT)
1 Armory Road
Wisteria Avenue Barstow Road 4,198
2 Barstow Road Muriel Drive 4,178
3 Muriel Drive Higgins Road 3,704
4 Higgins Road Montara Road 2,552
5 Barstow Road Virginia Way Mountain View Street 2,757
6 Mountain View Street E. Main Street 1,212
7 Broadway Avenue Armory Road Rimrock Road 1,840
8 E. Main Street
Barstow Road Seventh Avenue 4,582
9 Seventh Avenue Muriel Drive 6,048
10 Muriel Drive Yucca Avenue 6,205
11 Yucca Avenue Coolwater Lane 1,595
12 First Avenue Barstow Road 625
13 First Avenue
Main Street Hutchinson Street 2,047
14 Hutchinson Street Riverside Drive 6,809
15 Riverside Drive Irwin Road 6,438
16 Irwin Road Old Hwy 58 6,527
17 Lenwood Road
I-15/Outlet Center Dr Mercantile Way 6,528
18 Mercantile Way High Point Parkway 8,214
19 1,500 feet north of Commerce
Parkway W. Main Street 3,938
20 W. Main Street Jasper Road 1,814
21 Montara Road
Rimrock Road Forane Street 7,138
22 Forane Street Armory Road 4,084
23 Armory Road I-40 1,626
24 Mountain View Street
Avenue A First Avenue 3,351
25 First Avenue Barstow Road 812
26 Barstow Road Seventh Avenue 6,176
27 Seventh Street Lillian Drive 2,450
28 Lillian Drive Muriel Drive 1,450
29 Muriel Drive Yucca Avenue 1,402
30 Yucca Ave E. Main Street 1,413
31 Opal Ave Armory Road Rimrock Road 1,612

Executive Summary and Background
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 10 ID Street From To Average Daily Traffic
(ADT)
32 Rimrock Road
Agarita Ave H Street 1,548
33 Barstow Road Agarita Avenue 2,992
34 Princeton Drive Barstow Road 2,024
35 Princeton Drive Monterey Ave 2,929
36 Monterey Avenue Mesquite Drive 625
37 Mesquite Drive Montara Road 4,759
38 Roberta Street E. Main Street Virginia Way 731
39 W. Main Street
Western Drive Hwy 58 3,082
40 Hwy 58 Plaimor Avenue 3,480
41 Plaimor Avenue Laverne Avenue 3,947
42 Laverne Avenue L Street 3,827
43 L Street Avenue H 2,675
44 Avenue H Otis Avenue 1,924
45 Otis Avenue First Avenue 806
46 Avenue H W. Main Street I-15 1,001
47 Muriel Drive
Armory Road Rimrock Road 3,447
48 Rimrock Road Guadalupe Drive 3,133
49 Virginia Way Armory Road 5,751
50 Riverside Drive
First Avenue Railroad Track 4,194
51 Railroad Track Yucca Avenue 4,035
52 Yucca Avenue
Riverside Drive E. Main Street 4,726
53 E. Main Street Mountain View Street 6,217
54 Virginia Way
Barstow Road Mayor Helen Runyon Drive
(Lookout Drive) 6,997
55 Mayor Helen Runyon Drive
(Lookout Drive) Lillian Drive
7,305
56 Higgins Road Armory Road Rimrock Road 7,226
57 L Street I-15 Main Street 2,916
Executive Summary and Background
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 11 FIGURE 1.5 – EXISTING POSTED SPEED LIMITS
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 12

2.0 METHODOLOGY

DATA COLLECTION
Data was obtained regarding the prevailing speed of vehicles, visibility restrictions, roadway conditions, pedestrian activities, on-street parking, proximity of schools, and land use adjacent to the roadways. Radar speed measurements were conducted in August 2021 by AimTD LLC, following procedures established by State Law, guided by. Daily traffic counts were also collected by AimTD LLC. All traffic counts were conducted over a 24-hour period in August 2021 for seven consecutive days. Table 1.2 presents the existing Average Daily Traffic (ADT) for the surveyed streets in the City of Barstow.

The criteria and procedures described below were applied when using the electronic radar to measure vehicle speeds on selected streets within the City of Barstow. Traffic in both directions was recorded. The specific location on each street segment was selected after considering the following:
 Minimum stop sign or traffic signal influence
 Minimum visibility restrictions
 Non-congested traffic flows away from intersections, major driveways, crosswalks, railroad crossings, and unusual turning movements
 Minimum influence from parked vehicles, dips, curves, or roadway conditions that would affect the normal operation of a vehicle
The hours of radar operation were restricted to off-peak periods for heavily traveled streets, and to offpeak or non-congested peak periods on lightly traveled streets. All surveys were conducted in clear weather. The radar measurements were taken in an unmarked vehicle. A total of 100 samples were collected or up to one-hour of data collection for each street segment surveyed.

Following the speed survey data collection, speed data was organized into several categories to help inform the selection of a recommended speed. These categories include:
 85th Percentile Speed - The speed which 85% of surveyed motorists did not exceed during the data collection period
 50th Percentile (Median) Speed - The speed which 50% of surveyed motorists did not exceed during the data collection period, also referred to as the median speed.  10 mph pace Speed - The 10-mile per hour range containing the largest percentage of speed observations; provides an alternative and more readily identifiable measure to the standard deviation to describe the dispersion of speeds within the survey sample.  Average Speed - The calculated average speed of all surveyed vehicles. Also called mean speed.

COLLISION ANALYSIS
Collision data was obtained from the Statewide Integrated Traffic Records System (SWITRS). For purposes Methodology
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 13 of this study, information from the most recent 3-year period (depending on availability) was used to develop the collision statistics analyzed as a part of the Engineering and Traffic Survey. Collision data was obtained for the period from January 2018 to December 2020.

The collision analysis reviews the 3-year collision history across each study roadway segment to identify high frequency collisions areas. In order to only capture collisions that may have been affected by high vehicle speeds, only non-intersection collisions, as identified by SWITRS or within 50 feet of an intersection, were considered since intersection collisions often occur due to non-speed related factors.

Figure1.6 illustrates the collision data along the study roadways.

The prevailing collisions rate for each segment is calculated by first determining the total number of nonintersection collision for the 3-year period. Utilizing the Average Daily Traffic counts that were collected for this project, the length of each roadway segment length in miles, and the number of days for the selected study period (3 years), the prevailing collision rate is determined and normalized for every onemillion vehicles. This calculation is shown by the following formula:

Collision Rate (Collisions/MVM) = # of Collisions x 1,000,000 ADT x Segment Length x # of Days
In order to establish a baseline collision rate for the analysis, the collision rate for the study segments is compared to the statewide travel and crash rates for Urban (inside + outside city). The statewide collision rates are shown in Table 1.2.

Table 1.2 – Statewide Collision Summary by Lane Type for Urban Roadways Lane Type Collision Rate
2 and 3 lane 1.61
4 or more lanes undivided 1.32
4 or more lanes divided 1.34
Source: Caltrans 2018 Crash Data on California State Highways (road miles, travel, crashes, crash rates)

LAND USE AND ATTRACTORS
Identifying land uses and major attractors such schools and parks that may be prone to high pedestrian activity can help determine locations where slower speeds may be considered to maintain the safety of all users. Figure 1.7 and 1.8 shows the locations of residential and commercial land uses as well as parks and schools throughout the City.

Methodology
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 14 FIGURE 1.6 – CITYWIDE COLLISIONS ON STUDY SEGMENTS (2018-2020) Methodology
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 15 FIGURE 1.7 – CITYWIDE LAND USE AND SELECT ATTRACTORS – EAST/DOWNTOWN BARSTOW Survey
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 16 FIGURE 1.8 – CITYWIDE LAND USE AND SELECT ATTRACTORS – WEST BARSTOW

Survey
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 17

REVIEW CRITERIA
According to the California Vehicle Code as amended by AB-43, “The Department of Transportation shall, in the next scheduled revision, revise and thereafter maintain the California Manual on Uniform Traffic Control Devices to require the Department of Transportation or a local authority to round speed limits to the nearest five miles per hour of the 85th percentile of the free-flowing traffic. However, in cases in which the speed limit needs to be rounded up to the nearest five miles per hour increment of the 85th-percentile speed, the Department of Transportation or a local authority may decide to instead round down the speed limit to the lower five miles per hour increment. A local authority may additionally lower the speed limit as provided in Sections 22358.7 and 22358.8.”
Engineering and Traffic Survey is defined in CVC Section 627 as “a survey of highway and traffic conditions in accordance with methods determined by the Department of Transportation for use by state and local authorities”. The survey should include prevailing speeds determined by traffic engineering measurements and consideration of the following:
 CVC Section 627(b)(2) Accident records
 CVC Section 627(b)(3) Highway, traffic, and roadside conditions not readily apparent to the  driver
 CVC Section 627(c)(1) Residential density
 CVC Section 626(c)(2) Safety of bicyclists and pedestrians, with increased consideration for vulnerable pedestrian groups including children, seniors, persons with disabilities, users of personal assistive mobility devices, and the unhoused.

Accident record review is the most important criterion to determine whether the speed limit should be set for a reduction from the nearest 5 mph increment to the 85th percentile speed. Considerations for reductions from the 85th percentile speed are listed in CVC 627 and are based on the accident records and field condition review. The accident record review and speed reduction considerations for the selected street segments in the City of Barstow included the following items:
(1) Prevailing speeds as determined by traffic engineering measurements. (2) Accident records.
(3) Highway, traffic, and roadside conditions not readily apparent to the driver. (c) When conducting an engineering and traffic survey, local authorities, in addition to the factors set forth in paragraphs (1) to (3), inclusive, of subdivision (b) may consider all of the following:
(1) Residential density, if any of the following conditions exist on the particular portion of highway and the property contiguous thereto, other than a business district:
(A) Upon one side of the highway, within a distance of a quarter of a mile, the contiguous property fronting thereon is occupied by 13 or more separate dwelling houses or business structures. (B) Upon both sides of the highway, collectively, within a distance of a quarter of a mile, the contiguous property fronting thereon is occupied by 16 or more separate dwelling houses or business structures. (C) The portion of highway is longer than one-quarter of a mile but has the ratio of separate dwelling houses or business structures to the length of the highway described in either subparagraph (A) or (B). (2) Safety of bicyclists and pedestrians, with increased consideration for vulnerable pedestrian groups including children, seniors, persons with disabilities, users of personal assistive mobility devices, and the unhoused.

In some cases, the current speed limit is recommended to be retained in accordance with new CVC Section 22358.8(a), effective January 1, 2022.

Survey
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 18 If a local authority, after completing and engineering and traffic survey, finds that the speed limit is still more than is reasonable or safe, the local authority may, by ordinance, retain the current speed limit or restore the immediately prior speed limit if that speed limit was established with an engineering and traffic survey and if a registered engineer has evaluated the section of highway and determined that no additional general purpose lanes have been added to the roadway since completion of the traffic survey that established the prior speed limit.

CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 19

3.0 RESULTS AND RECOMMENDATIONS
After considering the 85th percentile speed indicated by the speed survey and engineering considerations not readily apparent to the driver, the proposed speed limit for most street segments remain the same as the existing speed limit. However, in six cases, the proposed speed limit is higher than existing and in one case, the proposed speed limit is lower than existing. There were four cases where the proposed speed limit is recommended to establish the posted speed limit for the study corridor.

Figure 3.1 illustrates the recommended speed limits.

RECOMMENDATIONS
The recommendations contained in this report are intended to establish or justify posted speed limits that can be enforced by radar. Posted speed limits advise the motorist and enforcement agencies of reasonable speed for a particular section of highway for prevailing conditions. They are not intended to be absolute. All violations of these speed limits are actually violations of the Basic Speed Law (Section 22350 of the CVC). This statute states that a person shall not drive a vehicle at a speed greater than is safe, having regard for traffic, roadway and weather conditions. A prima facie limit merely suggests a safe speed under normal conditions. Please see Appendix B for Engineering & Traffic Survey forms for each segment.

SPEED LIMIT CHANGES
The Engineering and Traffic Survey recommends the following speed limit changes based on the radar speed measurements and various non-apparent physical conditions:
 Armory Road between Wisteria Avenue and Barstow Road: This segment of Armory Road currently has no posted speed limit. Establish posted speed limit of 35 mph. The 85th percentile speed is 37.4 mph, rounded down to 35 mph. The accident rate is 32.49 MVM, which is higher than the expected rate of 1.61 MVM, which justifies lowering the speed limit below the 85th percentile speed.  Lenwood Road between I-15/Outlet Center Drive to Mercantile Way: Decrease existing posted speed limit of 65 mph to 55 mph. The 85th percentile speed is 54.2 mph, rounded up to 55 mph. There is also a nearby pedestrian generator (hotel and shopping center) with pedestrian activity along the corridor near Mercantile Way. The accident rate is lower than the expected rate, and there are no non-apparent physical conditions justifying the speed limit at the 85th percentile speed. The proposed 85th percentile speed limit is appropriate for this roadway.  Lenwood Road between 1,500 feet north of Commerce Parkway and W. Main Street: Increase existing posted speed limit of 50 mph to 55 mph. The 85th percentile speed is 52.9 mph, rounded up to 55 mph. The accident rate is lower than the expected rate, and there are no non-apparent physical conditions justifying the speed limit at the 85th percentile speed. The proposed 85th percentile speed limit is appropriate for this roadway.  Lenwood Road between W. Main Street and Jasper Road: This segment of Lenwood Road currently has no posted speed limit. Establish posted speed limit of 55 mph. The 85th percentile speed is 55.4 mph, rounded down to 55 mph. The accident rate is lower than the expected rate, and there are no Results and Recommendations
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 20 non-apparent physical conditions justifying the speed limit at the 85th percentile speed. The proposed 85th percentile speed limit is appropriate for this roadway.  Mountain View Street from Barstow Road to Seventh Avenue: Increase existing posted speed limit of 25 mph to 35 mph. The 85th percentile speed is 37.9 mph, rounded up to 40 mph. The accident rate is higher than the expected rate, and there is a nearby pedestrian generator (church) justifying the lowering of the speed limit below the 85th percentile speed.  Muriel Drive between Rimrock Road and Guadalupe Drive: This segment of Muriel Drive currently has no posted speed limit. Establish the posted speed limit of 40 mph. The 85th percentile speed is

45.1 mph, rounded down to 45 mph. To maintain continuity and avoid speed zones less than ½ mile and short transition zones, it is recommended that the 85th percentile speed of 45 mph be lowered to 40 mph.
 Riverside Drive between First Avenue and Railroad Tracks: Increase existing posted speed limit of 25 mph to 35 mph. The 85th percentile speed is 34.2 mph, rounded up to 35 mph. The accident rate is lower than the expected rate, and there are no non-apparent physical conditions justifying the speed limit at the 85th percentile speed. The proposed 85th percentile speed limit is appropriate for this roadway.
 Riverside Drive between Railroad Tracks and Yucca Avenue: Increase existing posted speed limit of 25 mph to 40 mph. The 85th percentile speed is 44.5 mph, rounded up to 45 mph. The roadway has horizontal and vertical curvatures and sight distance issues, therefore the 85th percentile speed is rounded down to 40 mph in accordance with CVC 22358.6.
 Virginia Way between Barstow Road and Mayor Helen Runyon Drive: Increase existing posted speed limit of 25 mph to 30 mph. The 85th percentile speed is 34.2 mph, rounded up to 35 mph. The accident rate is higher than the expected rate, and there are nearby pedestrian generators (park, shopping center and multi-family residential) along the roadway segment, which justifies lowering the speed limit below the 85th percentile speed of 35 mph to 30 mph.  Virginia Way between Mayor Helen Runyon Drive and Lillian Drive: Increase existing posted speed limit of 25 mph to 30 mph. The 85th percentile speed is 35.3 mph, rounded down to 35 mph. The accident rate is higher than the expected rate, there are nearby pedestrian generators (medical center and multi-family residential), and there is contiguous one-side frontage of 13 or more dwelling units in a ¼ mile along the roadway segment, which justifies lowering the speed limit below the 85th percentile speed of 35 mph to 30 mph.
 L Street between I-15 and Main Street: This segment of L Street currently has no posted speed limit.

Establish the posted speed limit of 45 mph. The 85th percentile speed is 46.2 mph, rounded down to 45 mph. There are no non-apparent physical conditions justifying lowering the speed limit below the 85th percentile speed.

Results and Recommendations
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 21 FIGURE 3.1 – RECOMMENDED SPEED LIMITS
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS PAGE 22

4.0 CERTIFICATION
This report constitutes the Engineering and Traffic Survey of speed limits within the City of Barstow. The existing speed limits were reviewed for adequacy in terms of adjacent land use, functional classification, traffic demands, speed surveys along individual roadways and speed limit continuity with neighboring jurisdictions. Traffic and roadside conditions not readily apparent to motorists were also considered.

The data collection technique is in compliance with Section 40802 of the California Vehicle Code (CVC).

The following reference materials were also used in the preparation of this Traffic and Engineering Survey:

1. California Vehicle Code (CVC) – California Department of Motor Vehicles, Sacramento.

2. Manual of Uniform Traffic Control Devices (MUTCD), California Supplement – State of California, Department of Transportation, Sacramento, California, Part 2, Section 2B.13.

All data utilized in this report is on file in the Community Services Department, Engineering Services Division, City of Barstow, 220 East Mountain View Street, Barstow, CA 92311.

The firm of KOA Corporation, on behalf of the City of Barstow, has prepared this document.

I, Walter Okitsu, do herby certify that I am a Registered Professional Engineer in the State of California. I have conducted this study for the City of Barstow, and this report was prepared under my supervision. Its contents are true and accurate to the best of my knowledge. ___________________________
Walter Okitsu, PE, PTOE, PTP, RSP21
Registered Professional Engineer (TR1406)
CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS
Appendix A – Engineering and Traffic Survey Forms for
Each Segment
Available for review at City Hall.

CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS
Appendix B – Average Daily Traffic (ADT) Count Data
Available for review at City Hall.

CITY OF BARSTOW | ENGINEERING AND TRAFFIC SURVEYS
Appendix C – Speed Zone Survey Data
Available for review at City Hall.