2011 TOWN OF CASTLE ROCK MOTOR VEHICLE ACCIDENT FACTS PREPARED BY THE PUBLIC WORKS DEPARTMENT

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1 2011 TOWN OF CASTLE ROCK MOTOR VEHICLE ACCIDENT FACTS PREPARED BY THE PUBLIC WORKS DEPARTMENT

2 ACKNOWLEDGEMENTS This report was assembled from data provided by the Castle Rock Police Department accident report data from the year Each accident record, whether completed by a local police officer or a member of the Colorado State Patrol, was sent to Castle Rock and entered into a centralized database maintained by the Public Works Department. The report itself was created by personnel in the Public Works Department. For more information, please contact: Transportation Engineering Division Town of Castle Rock 4175 N. Castleton Ct. Castle Rock, CO

3 Table of Contents Public Works Director s Letter i Executive Summary. 1 SECTION #1: Public Works Statistical Analysis 2 Road & Intersection Safety. 2 SECTION #2: 2011 Raw Data Summaries 5 Quick Facts 5 Accident Pin Map.. 6 Accident Rates by Location. 7 Time Trends. 10 Types of Crashes 11 Involvement by Age and Gender.. 12 Accident Location. 13 Accident Environment. 14 The Driver.. 15 Alcohol and Drug Involvement 16 Annual Trends 17 Definitions 20

Public Works Department Our mission is to provide outstanding service, safety and support for transportation infrastructure and maintenance.

4 Public Works Department Our mission is to provide outstanding service, safety and support for transportation infrastructure and maintenance. July 24, 2012 It is our pleasure to provide you with the 7th Annual Castle Rock Motor Vehicle Accident Facts Report. The accident data contained in this report will help to provide valuable information in making roadways safer within the Town of Castle Rock, by helping us determine what measures may be implemented to reduce accidents in a high-hazard area or intersection. It is our intent that the statistics provided will enable emergency services and design engineers alike, to gain a greater perspective in the goals of reducing traffic crashes and their severity. We will continue to dedicate our time and efforts toward the improvement of safety on our street system. Sincerely, Robert Goebel, P.E. Public Works Director Bob T. Watts, P.E. Transportation Planning and Traffic Engineering Manager i

5 EXECUTIVE SUMMARY The mission of the Public Works Department is To provide outstanding service, safety and support for transportation infrastructure and maintenance. One aspect of furthering this mission is analyzing accident data on a regular basis in order to identify where the roadway environment may be a contributing factor to accidents, developing options for improvements, and programming projects for correction. Since 2004, when Public Works first reported accident statistics, the numbers of fatalities, and persons injured have been declining. Additionally, the crash rate per town population has also been decreasing since These trends are encouraging indications of the overall safety of travel on Town roadways. are the result of many factors. These factors can generally be classified into three main categories: 1) human factors, 2) vehicle factors, and 3) roadway environment. By far, the largest percentage of accidents can be attributed to human factors. Sadly, these are the factors all of us who drive can control and are usually the simplest to correct. Basic driver awareness and respect for all users of the Town s roadways will go the farthest towards reducing the number of accidents. The tools to attack human factors and change driver behavior however aren t always effective. Getting the facts out to drivers, police enforcement, and the use of public awareness campaigns can assist with increasing awareness. However it will take conscious decisions by all drivers to change behavior when behind the wheel. Addressing vehicle factors is also the responsibility of everyone who owns and operates a motor vehicle. Ensuring that vehicles are in good shape to operate efficiently on the roads will also greatly assist with reducing the number of accidents. Regular vehicle inspections along with preventative maintenance procedures will help reduce the chances of an accident occurring as a result of a vehicle malfunction. The roadway environment is something that is out of the driver s control. The goal in this regard is to identify locations where roadways could be a contributing factor and implement treatments to correct these. Public Works uses statistical modeling to identify the locations where corrections to the roadway environment may improve safety. This helps direct limited resources to the locations where the most benefit can be obtained and avoids directing these resources toward locations where problems may not exist. The following intersection has been identified from several years of historical records as locations where roadway improvements may benefit transportation safety: Intersection Ownership Agency 1. Hwy 86 & Crowfoot Valley Rd CDOT The Colorado Department of Transportation (CDOT) will be provided with these findings and support provided where possible to assist them with further review of these locations for improvements. Road safety begins with all of us. Please remember to be courteous and cautious every time you get behind the wheel. 1

6 SECTION 1: Public Works Statistical Analysis The first section of this report summarizes the statistical review of the 2011 raw data. The purpose of this is to provide an initial screen to identify the signalized intersections that are producing accident numbers that exceed the number that may be expected to occur when compared to a model intersection sharing similar characteristics. Since accidents are expected to occur, it s important to determine which locations are experiencing accidents at a higher rate than should be expected. ROAD & INTERSECTION SAFETY One important goal from this accident data is to identify locations where the road environment may be a contributing factor to accidents. This is possible through statistical analysis. The roadway environment is something that is out of the driver s control. Part of the mission of the Town s Traffic Engineering and Operations Division is to assist with minimizing the number of roadway hazards that exist on Town roads that could contribute to accidents. The goal in this regard is to identify locations where roadways could be a contributing factor and implement treatments to correct these. The definition of the safety of a road section or intersection that the Traffic Engineering and Operations Division uses is the number of accidents expected to occur at these locations during a specified period. Because there are factors that are not related to the physical roadway environment that contribute to accidents, road sections and intersections are expected to have accidents occur. Since what is expected cannot be known, safety can only be estimated, and estimation is in degrees of precision. The precision of an estimate is usually expressed by its standard deviation. For practical reasons Traffic Engineering is interested in the safety of a road section or intersection that either requires attention because it seems to have too many accidents. If the estimation of safety is based only on accident counts or accident rates, the estimate would be biased. The existence of this regression-to-mean bias has been long recognized. It is known to produce inflated estimates of countermeasure effectiveness. To estimate roadway safety, Traffic Engineering utilizes the Empirical Bayes (EB) method. This method increases the precision of the estimates and corrects for the regression-to-mean bias. The EB method recognizes that accident counts or rates are not the only clue to safety. Another clue is in what is known about the safety of similar entities. To identify the safety of similar entities, safety performance functions (SPFs), which are models, need to be developed from existing data (accidents, vehicle volumes, etc.). SPF models from other jurisdictions can also be adopted if these SPFs are found to fit the Town s local trends. The refinement of SPFs increases as more data becomes available. This is important not only to identify locations with potential safety issues, but also to ensure that limited resources are not exhausted on problems that may not exist. As the Town s Traffic Engineering Division collects more accident records and continues to develop these SPFs, locations that seem to stand out as having a high accident rate will be looked into closer to determine if any accident trends are occurring that may indicate an issue that should be further examined. 2

7 Currently, only a model for signalized intersections has been developed. This is natural as signalized intersections exist on higher volume roads where accident probability is higher due to normal exposure. The Traffic Engineering and Operations Division will continue to collect data in hopes of developing SPFs for non-signalized intersections, and roadway segments when possible. A SPF has been developed for signalized intersections within the Town. This SPF provides an indication of the average number of accidents that are expected at similar signalized intersections. This combined with the actual accident records of each signalized site allows for a more precise safety estimate of each signalized intersection utilizing the EB method. The estimates improve with increased annual records. The tables on pages 8 and 9 are summaries of the signalized intersections with the highest accident rates for The results of the analysis provides an indication that the majority of signalized intersections are experiencing an accident rate that is consistent, or better, than signalized intersections that are similar in nature. The one exception was the intersection SH 86 / Crowfoot Valley Rd. which is under the control of CDOT. This information will be passed onto the Colorado Department of Transportation for their use along with intersection accident diagrams to allow for further assessment to determine if any improvements may be beneficial. For the remaining intersections, there is no indication that the roadway environment is causing a problem at these locations. This does not mean however that changes in the roadway environment could not increase intersection safety. However, since these accidents are more likely to be related to vehicle or human factors, spending a lot of resources on the roadway environment to try and increase the safety of these intersections would not likely be cost effective. In summary, everyone that utilizes the public roadway system has a responsibility when it comes to reducing the number of accidents. There are agencies that specialize in certain areas such as police enforcement, communications, education, and engineering that through their combined efforts will go a long way toward increasing the safety of the Town s roads The following tables summarize the 2011 highest accident rate locations (signalized). The actual accident total is shown for informational purposes only. The EB model uses this total within the formulas itself along with a weight to adjust for the fluctuation around the mean. As more years get added, the actual weighting decreases and the total number of accidents gets closer to the total expected. Locations with 1-year of data Intersection Actual # 3 Range of at Similar Location Peer Comparison Wilcox / Third St Similar Perry / Fifth St Similar 5th / Woodlands Blvd Similar Wolfensberger / Prairie Hawk Similar SH 86 / Woodlands Similar Meadows Pkwy. / Limelight Similar

8 Locations with 2-years of data Intersection Actual # 4 Range of at Similar Location Peer Comparison Front St. / Blackfeather Similar Factory Shops / New Memphis Similar Locations with 3-years of data Intersection Actual # Range of at Similar Location Peer Comparison Wilcox / Wolfensberger Similar Plum Crk Pkwy. / Wilcox Similar 1-25 / SH Better Locations with 4-years of data Intersection Actual # Range of at Similar Location Peer Comparison Wolfensberger / Park St Similar I-25 / US Better Locations with 5-years of data Intersection Actual # Range of at Similar Location Peer Comparison Meadows Blvd./Prairie Hawk Similar SH 86 / Fifth St Similar Locations with 6-years of data Intersection Actual # Range of at Similar Location Peer Comparison Wilcox St. / Fifth St Similar Plum Creek Pkwy. / Perry St Similar SH 86/Trailboss Better SH 86/Crowfoot Valley Rd Worse Locations with 7-years of data Intersection Actual # Range of at Similar Location Peer Comparison US 85 / Factory Shops Blvd Similar SH 86 / Allen Way Similar SH 86 / Front Similar US 85 / Meadows Pkwy Similar

9 SECTION 2: 2011 Raw Data Summaries This section summarizes the raw accident data for 2011 by various categories. The purpose of this is for general public interest as well as for use by other staff departments that may use this information to assist with improving their operations QUICK FACTS Persons Killed Persons Injured Reported On average, one traffic accident was reported every 14.8 hours. One out of every eleven accidents involved an injury. Of all drivers involved in accidents, 16% were age 19 years old, or less; 28% were under 25 years of age; and 10% were over the age of 60. Of all accidents 28% occurred at night. There were no pedestrian deaths in There were 0 fatalities among motorcycle or moped riders. 5

10 Accident Pin Map This map shows the distribution throughout the town of the 2011 accident locations. The arterial and collector streets have the highest incident of accidents, which is expected considering that they also have the highest traffic volumes. When reviewing new developments, we limit the number of new access points on these classifications of streets. By doing this, the potential for accidents decreases. 6

11 ACCIDENT RATES BY LOCATION Intersections # Avg. Volume Rate Rank based on Rate through intersection Factory Shops Blvd New Memphis Ct Fifth Woodlands Blvd SH Front St US Factory Shops Blvd US Meadows Pkwy Plum Creek Perry St Meadows Meadows Blvd SH Allen Wy SH Ridge Rd SH 86 and Trail Boss Dr US Plum Creek Wilcox St. Meadows Limelight Av SH Crowfoot Valley Rd SH Street Segments Number of Map location Average Daily Traffic Rate Rank Based on Rate SH ' E/O Ridge Rd Ridge Rd 528 S/O Fifth St Meadows Pkwy 528 W/O US SH N/O Crimson Sky Plum Creek Pkwy 300 E/O Emerald SH N/O Fifth St SH N/O Crimson Sky Note: Segment study was based on segments with at least 2 accidents in any location. 7

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14 TIME TRENDS MONTH OF YEAR % Deaths % January February March April May June July August September October November December Total DAY OF WEEK TIME OF DAY % Deaths % Midnight :00am :00am :00am :00am :00am :00am :00am :00am :00am :00am :00am :00pm :00pm :00pm :00pm :00pm :00pm :00pm :00pm :00pm :00pm :00pm :00pm Total % Deaths % Sunday Monday Tuesday Wednesday Thursday Friday Saturday Total

15 Number of Fatalities TYPES OF CRASHES FIRST HARMFUL EVENT Number of Injuries Number of % of Hit Other Vehicle Hit Fixed or Other Object Rollover Hit Animal Hit Pedestrian Hit Bicyclist Hit Railway Train Hit Parked Vehicle All Others TOTAL VEHICLE TYPE Vehicles Involved in % of Vehicles Auto SUV Pick-up Truck(over 10,000 lbs) 25 2 Motorcycle/Moped 12 1 Bicycle 11 1 Other 36 4 TOTAL

16 INVOLVEMENT BY AGE AND GENDER Note: 9% of accidents reported were unknown age/gender. Percent of Drivers Involved in Traffic by Age and Gender P e r c e n t Male Female Age 12

17 ACCIDENT LOCATION Intersections: Intersections By Classification Number Of Number Of People Killed Number Of People Injured Arterial/Arterial Arterial/Collector Collector/Collector Collector/Local Local/Local Total Non-Intersections: Segments Number of Number of People Killed Number of People Injured Multi-lane Arterial or Collector Two-lane Arterial Or Collector Local Total

18 ACCIDENT ENVIRONMENT Traffic control % Railroad Device 0 0 Yield Sign 0 0 Stop Sign Traffic Signal None Total Weather % Clear Rain 19 3 Snow/Sleet 42 8 Other 8 1 Total Road Conditions % Dry Wet 51 9 Icy/Slushy Other 19 3 Total Lighting Condition % Day Night Total

19 THE DRIVER Primary Cause of % Failed to Yield Right of Way Careless/Reckless Driving Violation of Red Signal 23 4 Unsafe Backing 16 3 Speeding too fast for 29 5 conditions Following too closely Turned Left in Front of 8 1 Approaching Traffic All Other/Unknown Total Condition of Drivers Drivers % No Defect or Unknown Other* ( includes: aggressive driving, fatigue, inexperienced drivers, distractions, illness) Cell Phone 6 1 *Alcohol related accidents are found in a separate table on the next page 15

20 ALCOHOL AND DRUG INVOLVEMENT Number of Involving Drivers Influenced by Alcohol or Drugs Age All Drivers Male Female < > Total

21 ANNUAL TRENDS Between 2004 and 2011, the Town s population increased by 43%. Considering the fact that an increase in accidents usually follows an increase in miles traveled which is closely correlated to population increases, our residents are not doing all that badly. As can be seen in the graph below, the number of accidents has remained within a fairly constant range for the past eight years. 17

The number of injury accidents and the corresponding injury accident rate have dramatically decreased since 2004.

22 The number of injury accidents and the corresponding injury accident rate have dramatically decreased since This could be due to more enforcement of the seat belt law, or to other factors such as a better observance of the speed limit. There are no patterns to the fatal accidents that have occurred. The one fatality recorded this year occurred when a car driven by a 20 year old left the roadway and struck a fixed object. The accident occurred during daylight hours; excessive speed was a contributing factor. 18

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24 DEFINITIONS The following special terms are used throughout this report, and are provided to clarify the meaning of the data. 1. Accident (or traffic accident): An unintended event involving a motor vehicle that causes death, injury, or property damage. 2. Alcohol Involvement Accident: Any motor vehicle accident in which a driver, pedestrian, or bicyclist had consumed alcohol. 3. Fatal Accident: A motor vehicle traffic accident which causes the death of one or more persons. 4. Hit-Other-Vehicle: A type of collision in which the first harmful event involves a collision between two or more vehicles. 5. Injury: A person sustaining injuries as the result of a motor vehicle traffic accident. This includes victims with the extent of injury of severe wound, other visible injury, or complaint of pain. Victims killed are not included in the injury category. 6. Motor Vehicle: Any motorized (mechanically or electrically powered) vehicle not operated on rails. 7. Other Non-collision: An event during an accident sequence which does not involve a collision with another vehicle or object. 8. Rollover: An accident in which the overturning of a vehicle was the first harmful event. 9. Type of Crash: The category which best describes the general type of collision which was the first event. 20

2008 TOWN OF CASTLE ROCK MOTOR VEHICLE ACCIDENT FACTS

2008 TOWN OF CASTLE ROCK MOTOR VEHICLE ACCIDENT FACTS 2008 TOWN OF CASTLE ROCK MOTOR VEHICLE ACCIDENT FACTS ACKNOWLEDGEMENTS This report was assembled from data provided by the Castle Rock Police Department