Exhibit “3”
Ordinance No. 3340
Engineering and Traffic Survey for Speed Limits 2021
(Page 1 of 13)
CITY OF CORONA
Riverside County, California
Public Works Department
2021
ENGINEERING AND TRAFFIC SURVEY
FOR SPEED LIMITS
TECHNICAL REPORT
PREPARED BY:
CITY OF CORONA
PUBLIC WORKS DEPARTMENT
TRAFFIC ENGINEERING
400 S. VICENTIA AVENUE, STE. 210
CORONA, CA 92882-2187
(951) 736-2266
Exhibit “3”
Ordinance No. 3340
Engineering and Traffic Survey for Speed Limits 2021
(Page 2 of 13)
CERTIFICATION
I, Rosalva N. Ureno, do hereby certify that this Engineering and Traffic Survey for the City of Corona was performed under my supervision. I certify that I am experienced in performing surveys of this type and duly registered in the State of California as a Professional Civil Engineer.
______________________ ___ ______________
Rosalva N. Ureno, P.E. No. 77433
City Traffic Engineer
Exhibit “3”
Ordinance No. 3340
Engineering and Traffic Survey for Speed Limits 2021
(Page 3 of 13)
2021 ENGINEERING AND TRAFFIC SURVEY FOR SPEED LIMITS
(SEE SECTION 3.3 FOR PROPOSED SPEED LIMITS)
1. INTRODUCTION
In accordance with procedures established by the State of California, this Engineering and Traffic Survey has been developed for the City of Corona as the basis for the establishment and enforcement of speed limits for selected streets within the City. The work herein was performed by the City to evaluate established speed limit sections to determine whether changes in pre-existing conditions have occurred which would require a modification to the speed limit.
The Traffic Engineering Division performs Engineering and Traffic Surveys for speed limits in accordance with the California Vehicle Code (CVC). Section 40802 of the CVC specifies the time periods within which speed surveys must be performed if the use of radar is to be employed to enforce speed limits. If such a survey is not performed within the required time frame, the new data and its use will constitute a speed trap. Hence, evidence using such data would not be admissible in court. CVC Section 40802(c)(2) defines a “speed trap” is either of the following:
(A) A section of a highway measured as to distance and with boundaries marked, designated or otherwise determined in order that the speed of a vehicle may be calculated by securing the time it takes the vehicle to travel the know distance.
(B) (i) A particular section of a highway with a prima facie speed limit that is provided by this code or by local ordinance under paragraph (1) of subdivision (b) of Section 22352, or established under Section 22354, 22357, 22358, or 22358.3, if that prima facie speed limit is not justified by an Engineering and Traffic Survey conducted within one of the following periods, prior to the date of the alleged violation, and enforcement of the speed limit involves the use of radar or other electronic devices that measure the speed of moving objects:
(I) Except as specified in subclause (II), seven years. (II) If an Engineering and Traffic Surveys was conducted more than seven years prior to the date of the alleged violation, and a registered engineer evaluates the selection of the highway and determines that no significant changes in roadway or traffic conditions have occurred, including, but not limited to, changes in adjoin property or land use, roadway width, or traffic volume, 10 years.
(ii) This subparagraph does not apply to a local street, road, or school zone.
Exhibit “3”
Ordinance No. 3340
Engineering and Traffic Survey for Speed Limits 2021
(Page 4 of 13)
2. PROCEDURES
2.1 ESTABLISHMENT OF SPEED ZONES
The reason that speed limit areas, and their required postings, are established is to guard reasonable drivers from the unreasonable behavior of reckless, unreliable, or otherwise dangerous drivers. As with other similar laws, the identified speed limits are based on the consensus of the majority of those who drive the highway as to what speed is reasonable and safe. It is this type of information that is reflected in the analysis section of this report. Namely, posted speed limits reflect the speed that most people deem to be safe, as opposed to a minority of drivers who do not drive in a reasonable manner.
Speed zones are also established to advise of road conditions or hazards which may not be readily apparent to a reasonable driver. For this reason, a field review of related road/traffic variables is included, which considers the analytical and accident history of a roadway segment to help determine a safe and reasonable speed limit.
2.2 DATA COLLECTION PROCEDURES
Speed evaluation data was collected at 43 different roadway segments in the City of Corona. These streets, and the number of segments on each street are described as follows:
• Auburndale Street (2)
• Auto Center Drive (1)
• Avenida Del Vista (2)
• Buchanan Street (1)
• Butterfield Drive (1)
• Cajalco Road (2)
• California Avenue (3)
• Chase Drive (3)
• Compton Avenue (1)
• Corona Avenue (1)
• Country Club Lane (1)
• Cresta Road (2)
• Crown Ranch Road (1)
• Gilbert Avenue (1)
• Magnolia Avenue (4)
• Main Street (1)
• Mangular Avenue (1)
• Montoya Drive (2)
• Mountain Gate Drive (1)
• Norco Hills Road (1)
• Old Temescal Road (3)
• Palisades Drive (1)
• Santana Way (2)
• Third Street (1)
• Upper Drive (1)
• Via Pacifica (1)
• Via Santiago (1)
• Vicentia Avenue (1)
As described in various traffic engineering documents, including information provided by the State of California, the selection of data collection locations for roadway segments on which radar data collection procedures were used involved considerations for the following:
Exhibit “3”
Ordinance No. 3340
Engineering and Traffic Survey for Speed Limits 2021
(Page 5 of 13)
1. Stop signs or traffic signal locations;
2. Visibility problems;
3. Traffic flow opportunities at or near intersections, major driveways, crosswalks, railroad crossings and unusual turning movements; and
4. Minimum influence from parked vehicles, bumps, dips, curves, or poor roadway conditions.
2.3 RADAR COLLECTION TIME-FRAMES
The hours of radar operations were restricted to off-peak periods (when possible) for heavily traveled streets, and to peak periods on lightly traveled streets. All speed surveys were conducted in fair weather.
The radar unit was mounted at the top of the front dash of an unmarked vehicle, with the meter-reading unit sustained inside the vehicle. The radar’s unit calibration was checked periodically using a tuning fork.
The radar operator recorded the radar speed meter readings for each location on Radar Speed Survey Field Sheets, included in the Appendix Sections of this Report.
In order for the sample to be representative of the actual traffic flow, a sample of at least 100 vehicles was taken in each survey. On low volume roads, where a total sample of 100 vehicles would result in an excessive time period, sampling was continued until a representative bell-shaped curve was attained. In no case did the sample contain less than 50 vehicles.
2.4 PREVAILING SPEEDS
The prevailing speeds are determined by speed zone surveys. The analysis of the prevailing speeds will provide important information about the existing traffic conditions. These are described in detail below.
• The CRITICAL SPEED, or 85th percentile speed, is defined as the speed at or below which 85 percent of the traffic is moving. From experience, traffic engineers have found that this is one of the most reliable factors in determining appropriate speed limits. Hence, the accepted practice, and one which has been used in this case, is to set the speed limit at the nearest 5 MPH increment to the critical speed. When this procedure is used, it not only conforms to that required by Federal and State regulations, but also provides a strong base for law enforcement personnel to properly enforce speed limits. • The 10 MPH PACE is the 10 MPH increment of speed where the largest number of recorded vehicles is contained. It is a measure of the dispersion of speeds within the sample surveyed. For this element, the accepted practice is to keep the recommended speed limit within the 10 MPH pace to Exhibit “3”
Ordinance No. 3340
Engineering and Traffic Survey for Speed Limits 2021
(Page 6 of 13)
the greatest extent possible, after considering the critical speed and any factors requiring a speed lower than the critical speed. • The MEDIAN SPEED, or 50th percentile speed, represents the mid-point value within the range of recorded speeds for a particular roadway section.
In other words, 50 percent of the vehicles travel faster than, and 50 percent travel slower than the median speed. This value is another measure of the central tendency of the vehicle speed distribution.
• The 15th PERCENTILE SPEED is the speed at or below which 15 percent of the vehicles are traveling. This value is important in determining the minimum allowable speed limit, given that the vehicles traveling below this speed tend to obstruct the flow of traffic, thereby increasing the accident potential.
The numerical values of the above factors are derived from the cumulative speed distribution curves which are calculated for each survey location. These distribution curves represent a method of graphical analysis which compares the cumulative percentage of vehicles to the speed at which the vehicles are traveling.
2.5 FIELD REVIEW
In addition to the availability of the statistical data discussed above, a significant aspect of speed limit recommendations is based on the field review. This is important, in that existing conditions may warrant a lower speed than what is actually indicated by the application of the survey data. Examples of the field data collected for the purposes of analyzing related roadway characteristics as they pertain to the determination of appropriate speed limits are listed below:
1. Segment length, width, and alignment;
2. Level of pedestrian activity;
3. Traffic flow characteristics;
4. Number of lanes and other channelization/striping factors;
5. Frequency of intersections, driveways and on-street parking;
6. Location of stop signs, traffic signals, and other regulatory traffic control devices;
7. Roadway condition, bumps, and dips;
8. Obstructions to drive/pedestrian visibility;
9. Land use and proximity of schools;
10. Uniformity with existing speed zones to/with adjacent jurisdictions; and Exhibit “3”
Ordinance No. 3340
Engineering and Traffic Survey for Speed Limits 2021
(Page 7 of 13)
11. Any other unusual conditions or hazards not readily apparent to the driver.
The results of the field review of related road/traffic variables are summarized on the Engineering and Traffic Survey forms found in the Appendix of this report.
2.6 ACCIDENT HISTORY
The Engineering and Traffic Survey forms summarize the available accident information for the subject streets. The accident information includes the total number of accidents within each street segment, and of those accidents, the number which are speed-related. This information is obtained from the City of Corona computerized accident database. The annual accident rate figures represent the number of speed-related accidents divided by two years of accident records.
The equation for calculating roadway segment accident rates is as follows:
Accident Rate per HMVM (100 Million Vehicle Miles) =
(No. of accidents in one year) x (100,000,000
(Average Daily Traffic) x (365) x (Distance of Segment in Miles) Source: Institute of Transportation Engineers, Traffic Engineering Handbook 6th ed., Washington D.C.: ITE, 2010
3. RESULTS AND RECOMMENDATIONS
Several factors are considered when determining recommendations for speed limits. These important factors include the prevailing speeds, as determined by the radar speed surveys; the accident history; and the existing traffic and roadside conditions not readily apparent to the driver. Per the California Manual on Uniform Traffic Control Devices (CA MUTCD) Section 2B.13, the posted speed is established at the nearest 5 MPH increment of the 85th percentile speed of free-flow traffic, except as shown in the two options below.
Option 1: Whenever engineering study indicates the need for a reduction in speed to match existing conditions with the traffic safety needs of the community, the posted speed may be reduced by 5 MPH from the nearest 5 MPH increment of the 85th percentile speed, provided that the conditions and justification for the lower speed limit is documented in writing in the E&TS and approved by a registered Civil or Traffic Engineer. The conditions and justifications for those street segments with lower speed limits are provided in Section 3.2 herein.
Option 2: For cases in which the nearest 5 MPH increment of the 85th percentile speed would require a rounding up, then the speed limit may be rounded down to the nearest 5 MPH increment below the 85th percentile speed, if no further reduction is used.
Exhibit “3”
Ordinance No. 3340
Engineering and Traffic Survey for Speed Limits 2021
(Page 8 of 13)
Section 3.3 summarizes the results and recommendations of the radar speed survey for the selected locations. As shown, the table presents the necessary analysis elements that, in addition to the field review of a registered Civil Engineer, led to the recommendations indicated.
3.1 NO CHANGES TO EXISTING SPEED LIMITS
Section 3.3 indicates that 42 of 43 street segments are recommended for no change in posted speed limits. The reason centers mostly on the fact that newly measured values of the 85th percentile and the 10 MPH pace are still within the parameters of the existing speed limits. Hence, the current postings should remain as is. Those locations are listed below:
• Auburndale Street
River to Palos Verdes
Palos Verdes to Rincon
• Auto Center Drive
SR-91 to Railroad1
• Avenida Del Vista
Yucca to Via Del Rio
Via Del Rio to Sixth
• Buchanan Street
Promenade to Wimbledon
• Butterfield Drive
Smith to Clearwater
• Cajalco Road
I-15 to Temescal Canyon
Temescal Canyon to City Limits
• California Avenue
Rimpau to Ontario
Ontario to Foothill
Foothill to Valencia
• Chase Drive
Mangular to Via Mazatlan1
Main to Hudson
Tarocco to California
• Compton Avenue
Ontario to Pico
• Corona Avenue
Gise to Parkridge
• Country Club Lane
River to Greenbriar1
• Cresta Road
Parkridge to Termino
Termino to Promenade
• Crown Ranch Road
Cleveland to End
• Gilbert Avenue
Hidden Springs to Cleveland1
• Magnolia Avenue
Main to Ontario1
Ontario to Fullerton
Fullerton to I-15 Fwy
I-15 Fwy to Sixth
• Main Street
Upper to Mountain Gate
• Mangular Avenue
Ontario to Chase1
• Montoya Drive
Main to Buena Vista
Buena Vista to Highgrove
• Norco Hills Road
Hidden Valley to Parkview
• Old Temescal Road
King Fisher to Fullerton
Fullerton to Rimpau
Rimpau to Compton
Exhibit “3”
Ordinance No. 3340
Engineering and Traffic Survey for Speed Limits 2021
(Page 9 of 13)
• Palisades Drive
Green River to Serfas Club
• Santana Way
Magnolia to Fullerton
Fullerton to Taber
• Third Street
W. Grand to W. Grand1
• Upper Drive
Lemon Grove to Valencia
• Via Pacifica
Ontario to Border
• Via Santiago
Border to Avenida Del Vista
• Vicentia Avenue
Sixth to Second
1Speed limit reduction with justifications per
CA MUTCD Section 2B.13 (see Section 3.2
herein for justifications)
3.2 NO CHANGE TO EXISTING SPEED LIMITS WITH JUSTIFICATIONS This Section presents the conditions and justifications for those street segments that are to remain unchanged after the 5 MPH reduction per the California MUTCD standards Section 2B.13. The speed reduction is necessary to facilitate the orderly movement of traffic, and the reasons for the lower speed limit compliant with CVC Sections 627 and 22358.5.
Auto Center Drive from SR-91 to Railroad (35 MPH)
This segment of Auto Center Drive is a four-lane, undivided secondary arterial that is 0.55 miles in length, and serves 24,500 vehicles per day. The West Corona Metrolink station is located at the south end of the roadway segment There are multiple horizontal and vertical curves along the entire segment of the road which raises concern for safe stopping distance that is not readily apparent to the motorist.
To maintain safe stopping distance and ensure adequate egress opportunities for commuters patronizing the Metrolink Station, it is recommended that the current 35 MPH limit be maintained.
Chase Drive from Mangular to Via Mazatlan (25 MPH)
Chase Drive is a two-lane undivided local street varying from 25 feet to 40 feet wide. The street is 0.54 miles in length and carries 1,800 vehicles per day. The west end of this roadway segment is fronted by homes to the south and a detention basin on the north. The remainder of the street serves residential uses via side streets. In addition, there are multiple driveways and multiple horizontal curves along the entire segment of the road which raises concern for safe stopping distance that is not readily apparent to the motorist. To maintain safe stopping sight distance and to ensure adequate egress opportunities for residents on Chase Drive, it is recommended that the current speed limit of 25 MPH be maintained.
Country Club Lane from River to Greenbriar (35 MPH)
Country Club Lane is a two-lane undivided local residential that is 0.45 miles in length and carries 2,100 vehicles per day. This street has class II bike lanes and on-street parking on both sides and serves residential uses via front-loading Exhibit “3”
Ordinance No. 3340
Engineering and Traffic Survey for Speed Limits 2021
(Page 10 of 13)
driveways and side streets. To maintain safe conditions and to provide motorists adequate reaction time to slow down for vehicles accessing the residential driveways, Country Club Lane should retain the existing posted speed limit of 35 MPH.
Gilbert Avenue from Hidden Springs to Cleveland (35 MPH) Gilbert Avenue is a two-lane, undivided local residential street that is 0.8 miles in length and carries 1,800 vehicles per day. This street serves mainly as a collector for the residential properties in the area via multiple side streets. There is a gradual downgrade along the entire segment of the road which raises concern for a safe stopping sight distance that is not readily apparent to the motorists. To ensure adequate egress opportunities onto Gilbert Avenue for the residential properties without increasing the risk of broadside accidents, this segment of Gilbert Avenue should retain the existing posted speed limit of 35 MPH.
Magnolia Avenue from Main to Ontario (40 MPH)
This segment of Magnolia Avenue is a four-lane, divided major arterial that is 0.55 miles in length, and serves 12,600 vehicles per day. This segment serves residential uses via side streets, a shopping center via front-loading driveways, a high school on the west end and a park at the east end. The segment is characterized with raised medians and class II bike lanes. In addition, this segment has multiple horizontal curves which limit lateral visibility of the street, creating a line-of-sight concern. To maintain safe conditions and ensure adequate egress opportunities onto Magnolia Avenue, it is recommended that the current 40 MPH limit be maintained.
Mangular Avenue from Ontario to Chase (35 MPH)
Mangular Avenue is a two-lane undivided local residential that is 1.01 miles in length and carries 6,300 vehicles per day. This street has class II bike lanes and on-street parking on both sides and serves residential uses via front-loading driveways and side streets. To maintain safe conditions and to provide motorists adequate reaction time to slow down for vehicles accessing the residential driveways, Mangular Avenue should retain the existing posted speed limit of 35 MPH.
Third Street from W. Grand to E. Grand (35 MPH)
This segment of Third Street is a two-lane, undivided collector that is 0.77 miles in length and serves 3,200 vehicles per day. This segment serves residential uses via side streets and is also fronted by residential driveways and alleyway access points.
There is on-street parking on both sides of the street with a public park and youth center on the west end of the segment. To maintain safe conditions for pedestrians and to ensure adequate egress opportunities onto Third Street, it is recommended that the current 35 MPH limit be maintained.
Exhibit “3”
Ordinance No. 3340
Engineering and Traffic Survey for Speed Limits 2021
(Page 11 of 13)
3.3 CHANGES TO EXISTING SPEED LIMITS
There is one street segment where the findings of the speed survey justify decreasing the posted speed limit from 40 MPH to 35 MPH. The recommended speed limit is based on the 85th percentile speed, 10 MPH pace, median speed, roadway characteristics, and accident statistics. The decreased speed limit location is as follows:
• Mountain Gate Drive
Lincoln to Main
Mountain Gate Drive from Lincoln to Main (35 MPH)
Mountain Gate Drive is a two-lane, undivided collector that is 0.77 miles in length, and carries 9,200 vehicles per day. The street serves mainly residential uses via side streets, with an elementary school and a public park. There are multiple horizontal curves along the entire segment of the road, which raise concerns regarding a safe stopping distance that may not be readily apparent to the motorist.
The segment is fronted by an elementary school, which experiences heavy vehicular and student traffic during school let-in/let-out times. Crossing guards at the intersections of Lincoln at Mountain Gate and Mountain Gate at Rowena assist pedestrians and students during school let-in/let-out times. It is recommended that the existing 40 MPH be reduced to 35 MPH to maintain safe conditions for pedestrians and students, and to ensure adequate egress opportunities onto Mountain Gate Drive from the school driveways.
Exhibit “3”
Ordinance No. 3340
Engineering and Traffic Survey for Speed Limits 2021
(Page 12 of 13)
3.3 PROPOSED SPEED LIMITS
SPEED
STREET LIMITS
EXISTING
CRITICAL1
(85%-
TILE)
PROPOSED
Auburndale Street River to Palos Verdes 25 24.9 25
Palos Verdes to Rincon 35 39.1 35
Auto Center Drive SR-91 to Railroad 35 44 35
Avenida Del Vista Yucca to Via Del Rio 35 38.5 35
Via Del Rio to Sixth 35 30.4 35
Buchanan Street Promenade to Wimbledon 40 38.4 40
Butterfield Drive Smith to Clearwater 40 39.5 40
Cajalco Road I-15 to Temescal Canyon 45 48.5 45
Temescal Canyon to City Limits 45 42.8 45
California Avenue Rimpau to Ontario 40 41.8 40
Ontario to Foothill 45 47.8 45
Foothill to Valencia 45 44.3 45
Chase Drive Mangular to Via Mazatlan 25 32.1 25
Main to Hudson 35 37.7 35
Tarocco to California 35 37.4 35
Compton Avenue Ontario to Pico 40 42.2 40
Corona Avenue Gise to Parkridge 35 39.5 35
Country Club Lane River to Greenbriar 35 41.1 35
Cresta Road Parkridge to Termino 35 38.2 35
Termino to Promenade 30 33.8 30
Crown Ranch Road Cleveland to End 35 37.3 35
Gilbert Avenue Hidden Springs to Cleveland 35 41.4 35
Magnolia Avenue Main to Ontario 40 45.7 40
Ontario to Fullerton 40 43.7 40
Fullerton to I-15 FWY 40 43.8 40
I-15 FWY to Sixth 45 46.0 45
Main Street Upper to Mountain Gate 40 44.4 40
Exhibit “3”
Ordinance No. 3340
Engineering and Traffic Survey for Speed Limits 2021
(Page 13 of 13)
SPEED
STREET LIMITS
EXISTING
CRITICAL1
(85%-
TILE)
PROPOSED
Mangular Avenue Ontario to Chase 35 41.1 35
Montoya Drive Main to Buena Vista 35 38.8 35
Buena Vista to Highgrove 35 37.8 35
Mountain Gate Drive Lincoln to Main 40 43.1 35
Norco Hills Road Hidden Valley to Parkview 50 49.1 50
Old Temescal Road Kingfisher to Fullerton 35 36.4 35
Fullerton to Rimpau 40 41.1 40
Rimpau to Compton 40 40.0 40
Palisades Drive Green River to Serfas Club 50 54.5 50
Santana Way Magnolia to Fullerton 35 39.1 35
Fullerton to Taber 35 37.4 35
Third Street W. Grand to E. Grand 30 38.0 30
Upper Drive Lemon Grove to Valencia 45 43.1 45
Via Pacifica Ontario to Border 40 42.0 40
Via Santiago Border to Avenida Del Vista 35 38.3 35
Vicentia Avenue Sixth to Second 30 34.7 30
NOTES:
1. The CRITICAL SPEED, or 85th percentile speed, is defined as that speed at or below which 85 percent of the traffic is moving. From experience, traffic engineers have found that this is one of the most reliable factors in determining appropriate speed limits. Hence, the accepted practice, and one which has been used in this case, is to set the speed limit at the nearest 5 MPH increment to the critical speed. When this procedure is used, it not only conforms to that required by the State but also provides a strong base for law enforcement personnel to properly enforce speed limits.