Road Safety 101 At the conclusion of this module, participants will be able to:   Articulate a comprehensive definition of road safety. Additional Instructor Preparation for this Module:   Add an introduction slide with your name(s) and information. Be prepared to point out the location of the restrooms in the facility. Material Preparation: Flip chart, markers, pens/pencils, name tents, sign-in form Before the course: Have all participants fill out the Sign-in Form. Pass out name tents. Pass out the Participant Guide before the course starts.

Tracking Your Progress Through Highway Safety Core Competencies Core Competency 1: Core Competency 2: Core Competency 3: Core Competency 4: Core Competency 5: The Nature of Road Safety The History and Institutional Settings of Road Safety Management The Origins, Characteristics, and Uses of Crash Data Contributing Crash Factors, Countermeasure Selection, and Evaluation Road Safety Program Management Road Safety 101 is based on a set of core competencies developed by a TRB Joint Subcommittee. The idea is that transportation safety professionals and practitioners should all have a basic knowledge of the fundamentals of road safety. The basic knowledge supports the development of a road safety discipline as well as a common language. The five core competencies are: The Nature of Road Safety The History and Institutional Settings of Road Safety Management The Origins, Characteristics, and Uses of Crash Data Contributing Crash Factors, Countermeasure Selection, and Evaluation Road Safety Program Management NCHRP 17-40, June 2010

The Nature of Road Safety The first competency or unit explores the nature of road safety. NCHRP 17-40, June 2010

Tracking your way through Road Safety 101 Core Competency 1: The Nature of Road Safety Module 1: Road Safety Defined From a Science-Based Perspective Module 2: Road Safety – A Complex Field Module 3: Road Safety Demographics Module 4: Road User Decisions Module 5: Science-Based Road Safety Research Module 6: Intervention Tools and Countermeasures This unit seeks to increase understanding of the complex, multidisciplinary nature of road safety and lay the groundwork for moving to a more science-based approach in our work. The specific topics we will address are: Road Safety Defined From a Science-Based Perspective Road Safety – A Complex Field Road Safety Demographics Road User Decisions Science-Based Road Safety Research, and Intervention Tools and Countermeasures NCHRP 17-40, June 2010

Road Safety Defined Articulate a comprehensive definition of road safety. The purpose of this module is to define and examine various perspectives on road safety. Once again, we need to emphasize the “fundamental” nature of the course. Defining safety is of the fundamentals, but you might be interested to know, a universal definition of safety does not exist! NCHRP 17-40, June 2010

Exercise 1: Defining Safety How do you define safety? Before we go further, take a minute to write down a definition of safety from your own perspective. How would you define safety? Imagine you are speaking with someone who just learning English and the person asks you what safety means. How would you define it for them? NCHRP 17-40, June 2010 5 5 5

Various Definitions Public health Highway safety professional Design, maintenance, or operations engineer Transit Human Factors The definition of transportation safety varies among disciplines, modes of transportation, and organizations. Public health professionals, state safety professionals, design, maintenance, or operations engineers, and transit planners might view safety very differently. Ask: How might their definitions differ? Answer: The public health view of road safety is crashes constitute one of many events causing injuries in our daily lives. Public health experts view driving risk in terms of the risk it poses relative to other major public health risks, such as cancer, heart disease, stroke, obesity, suicide, homicide, etc. In such comparisons exposure to risk becomes an important metric. A state safety professional or transportation engineer might view safety from an operations perspective. Safety from this perspective is defined based on meeting standards identified by the Manual of Uniform Traffic Control Devices (MUTCD) and the AASHTO Green Book. The assumption is that meeting the standard is safe. Transit safety focuses on personal safety. Transit is relatively safe, but it can be made safer. Transit often shares the same facilities used by automobiles and trucks. Transit passengers, operators, and motorists play a role in the definition of safety where transit is concerned. Passengers are especially vulnerable to injury when shifting from one mode of transportation to another as pedestrians. A human factors engineer or psychologist might define safety in terms of the road users’ interactions with their vehicles and the roadway and believe the ease and transparency of the interaction defines safe and unsafe. NCHRP 17-40, June 2010 6 6 6

Major Topics The Science-Based Perspective The Dynamics of a Crash Models for Understanding and Explaining Crashes In our attempt to define and understand the nature of road safety, we will discuss these topics: Road Safety Defined from a Science-Based Perspective The Dynamics of a Crash, and Models for Understanding and Explaining Crashes We all use models on a regular basis. For example, if you are managing traffic at a crash scene; you undoubtedly have something in your head that gives you a picture of what needs to be done. Hence, you have a model image. We won’t make you into a scientist in this course, but we will lead you in that direction. Road safety is a major public health and economic issue. On average each year, over 4 million motor vehicle crashes result in more than 40,000 fatalities and 2.5 million injuries in the United States alone (NHTSA, 2008). This ranks motor vehicle crashes as the sixth leading cause of death and the leading cause of injuries in the United States. In addition to the resulting injuries and life lost, crashes also result in a significant economic loss. In 2000, it was estimated traffic crashes in the United States accounted for over $230 billion in economic losses (Blincoe et al., 2000). Road safety professionals work hard to reduce the number and severity of crashes. The road safety profession involves the expertise of individuals from multiple disciplines, multiple modes of road transportation, and the network has a real and measurable impact on crashes and crash severity. While each of these disciplines has contributed to significant improvements in road safety over the last 40 years, measures have often been implemented in isolation. In the future, synergies and cooperation across disciplines will need to be established if continual improvements in road safety are to be realized. NCHRP 17-40, June 2010

A Definition of Road Safety “ Roadway safety is the number of accidents (crashes), or accident consequences, by kind and severity, expected to occur on the entity during a specific period. Ezra Hauer Road safety is the study of crashes and their harm on the surface transportation system; hence our focus is on outcomes such as fatalities and serious injuries rather than outputs, such as number of arrests, trainings, etc. An entity is anything we want to study. Remember the focus on consequences “expected” to ocur. This is an important concept and we will return to it many times throughout the course. An “accident” implies that the outcome is unintentional, as in the phrase “it was an accident”. Often motor vehicle accidents are referred to as crashes – a term that implies preventability. Regardless of whether accident or crash is used, both terms refer to collisions among motor vehicles and their occupants, as well as pedestrians, bicyclists, motorcyclists, and other users of the roadway. These events are studied by safety professionals to learn more effective prevention measures. Science-based road safety is the scientific study of accidents or crashes on roadways. The study has two critical underlying concepts. The first is the definition of safety from the perspective of the transportation systems analyst (Hauer, Observational Before-After Studies in Road Safety, Pergamon. 1997): “Roadway Safety is the number of accidents (crashes), or accident consequences, by kind and severity, expected to occur on the entity during a specific period.” Notice the emphasis is on event outcomes, i.e. crashes injuries and property damage. These measures should be used whenever possible to quantify safety; other measures such as incidents, near misses, violations, and the like may be indicative of safety problems, but the preferred measure of safety is one that characterizes the outcome of the event. An entity is a specific type of highway facility, such as a signalized intersection, an interstate on-ramp, a rural highway segment, or a driver or vehicle group. The expected safety is not necessarily the observed safety at an entity. Often the expected safety is the unobserved underlying true safety of the entity, whereas the observed safety is subject to random fluctuations in crashes. It is important to remember this concept. Additional discussion on this topic will occur in Unit 4. “ NCHRP 17-40, June 2010

National Highway Fatalities and Fatality Rates 1988-2008* Let’s look at the national trends based on two commonly used performance measures. This slide shows that we have made progress in reducing fatalities and injuries since 1988. While the fatality rate (in red) declined, the actual number of fatalities remained fairly flat over the decade leading up to 2006. Ask: What does this mean? It simply means that VMT has increased more than fatalities so the rate goes down even though the actual number may not have changed much. We will discuss this concept again later in the course. Many argue in contemporary times that the raw number should always be used in setting goals, developing performance measures, and informing the public. This argument holds that use of rates simply camouflages the seriousness of the problem and, furthermore, one death is one too many. (Iowa’s tagline) Of course the picture changes in 2007 and 2008 when the nation experienced a significant decline in the number of fatalities and injuries. This is in part due to the increased price of fuel and the declining economy. In addition, the 9.1 % decline in fatality rate corresponded to a 3.6% decline in VMT, (2007 to 2008). However, the exact nature and contributing factors to the latest decline have yet to be sorted out. Source: Created by Cambridge Systematics based on fatality data retrieved from the Fatality Analysis Reporting System (National Highway Traffic Safety Administration) and vehicle miles traveled data (Federal Highway Administration. *2008 Preliminary data retrieved from NHTSA Traffic Safety Facts Research Note DOT HS 811 124 9 9 9 NCHRP 17-40, June 2010 9 9 9

National Highway Injuries and Injury Rates This slide shows a similar decline in national injuries and injury rates from 1988 to 2007. 2008 data were not available when this script was written. What reasons can you give for the decline in injuries from 1988 to 2006? (Hint: This is probably due to dramatic increase in safety belt use; introducing airbags into the vehicle fleet and other vehicle improvements such as electronic stability control, etc. It may also be due to systemwide roadway improvements such as the installation of rumble strips and stripes, upgraded guardrail, median cable barrier, etc.) Source: Created by Cambridge Systematics based on injury data retrieved from NHTSA Traffic Crash Facts 2007 1010 NCHRP 17-40, June 2010 10 10 10

The Public Health Perspective Events Causing Health Problems Cancer Heart disease Stroke Obesity Suicide Homicide Population or Population Category Cancer cases per capita Number of attempted suicides by age and gender categories Exposure to Risk The public health view of road safety is crashes constitute one of many events causing injuries in our daily lives. Public health experts view driving risk in terms of the risk it poses relative to other major public health risks, such as cancer, heart disease, stroke, obesity, suicide, homicide, etc. In such comparisons exposure to risk becomes an important metric. Exposure in public health is usually measured by population or population category (e.g., cancer rates are often provided in terms of cancer cases per capita, and suicide rates are provided as number of attempted suicides by age and gender categories). NCHRP 17-40, June 2010

10 Leading Causes of Death by Age Group, United States─ 2006 This table compares road casualties to other illnesses by age group. The Table shows in general, driving risk for young people is extremely high. In fact it is the leading cause of death for all people between the ages of 1 and 34. However, older people experience less risk and by age 65, it doesn’t even make the chart. Question: Why do you think people over 65 are at less risk of being involved in fatal crashes? Answer: Older people drive less so they are exposed to less risk. They also are more likely to wear safety belts and less likely to speed or drive impaired than younger age groups. However, if they are involved in a crash, increasing frailty due to the normal aging process increases the likelihood they will be injured or killed. Another reason is that as people age, cancer and heart disease take a larger toll than in younger age cohorts. NCHRP 17-40, June 2010

The energy an object possesses The Dynamics of a Crash Kinetic Energy: The energy an object possesses because of its motion Crashes occur when bodies (entire vehicle, occupants, baggage, etc.) in motion collide. Three stages occur in most crashes. First, the vehicle hits something; second, the occupants hit the inside of the vehicle; and finally, internal organs slam against the skeletal structure. The forces and energy involved in crashes can become quite extreme. Analyzing the forces in a motor vehicle crash is a complex undertaking. When a car is traveling along a road it has a certain amount of energy, called kinetic (motion) energy. In normal driving, kinetic energy is converted to heat through braking (brake pads to rotors and rubber to pavement). In fact normal driving is a repetitive exercise of converting kinetic energy to heat. In a motor vehicle crash, kinetic energy is converted to heat (tires, metal, etc.), friction losses (tires, scraping, etc.), and crush energy (deformation of car and human parts). The scope of this workshop will not cover the equations involved in calculating crash energy but consider one example. If a 3000 lb car is traveling at 60 mph (88 ft/sec) and collides with a solid wall, what is the crush depth of the vehicle (assume wall does not crush at all)? The answer is the car must be crushed 4.9 feet to convert all of the kinetic energy to crush energy. Hopefully the car is designed to sustain 4.9 feet of crush damage without harming the occupants. NCHRP 17-40, June 2010

The Dynamics of a Crash The Dynamics of a Crash Slide 2: Explain and define crush energy (include image below) Suppose instead that the driver was able to reduce speed by 20 mph by applying the brakes prior to impact (converting some of the kinetic energy to heat energy), what would the crush depth in this scenario? The crush damage is substantially less as a result of applying the brakes. This outcome may represent the difference between being killed and walking away from the accident unharmed. Some important concepts related to crash dynamics are: Kinetic energy of motion is converted to heat, friction, and crush damage. Converting kinetic energy to heat through braking represents normal driving. Crash “survivability” is related to how energy is absorbed by the vehicle and passengers. In general the smaller the energy and the greater the time permitted to absorb the energy, the more survivable the crash. Crush energy: Deformation of car and human parts NCHRP 17-40, June 2010

Crash Models and Road Safety Road safety professionals make extensive use of statistical crash models to gain insight into the performance of roadway locations. Often locations are broken down into similar types for analysis, such as roadway segments, ramps, and intersections. Identification of similar facilities for analysis is justified because facilities will perform differently with respect to safety because of the different functions they perform and because of the different environments in which they are built and operate. Examples of sites that might be modeled include: Rural two-lane highway segments Urban signalized intersections Freeway on-ramps Safety (e.g. fatal and injury crashes, etc.) is often modeled as a function of important factors that influence safety, such as roadway, environment, and driver factors. The Highway Safety Manual modules are based on facility type where the crashes occur because our expectations re crash occurrence will vary by road type. This course will later delve deeper into safety modeling and analysis. NCHRP 17-40, June 2010

Driver Behavior and Crash Models Another perspective on which to view transportation safety is through the eyes of a driver. Unlike road safety models which examine safety from the perspective of the transportation network, driver behavior and environmental models examine safety from the perspective of the road user. Statistical models are also used to explore the relationships between drivers and factors that influence their safety. Many road user groups warrant special attention and are the subject of substantial research, such as: Young and inexperienced drivers Older drivers Heavy vehicle operators Rural vs. urban drivers Aggressive drivers and speeders Motorcyclists Pedestrians Bicyclists For example, what’s going on in this picture. What driver practices might contribute to driver error? Answers: talking on the cell phone, putting on make up, where she is looking, and no seatbelt use. We will examine specific methods for studying different road user groups in Unit 4. Currently, the Strategic Highway Research Program II (SHRP-2) is conducting a large number of studies involving instrumented vehicles. These studies will examine driver behavior in a natural environment to learn more about crash contributing factors. NCHRP 17-40, June 2010

Multidisciplinary Approaches Understanding motor vehicle crashes and contributing crash factors requires a multidisciplinary perspective. Applying a broad perspective to motor vehicle crashes is difficult due to the compartmentalization that naturally occurs. Departments of transportation (local, state, federal) are responsible for roadway countermeasures, while behavioral countermeasures are often considered by health agencies, the medical and insurance communities, state highway safety offices, motor carrier safety representatives, and advocacy groups. Although a multi-disciplinary approach is desired, it is often difficult to achieve. The graphic on this slide shows the interaction effect. For example, 24 percent of crashes involve factors associated with both the roadway and road user behavior. NCHRP 17-40, June 2010

Review Road Safety Defined from a Science-Based Perspective The Dynamics of a Crash Models for Understanding and Explaining Crashes This module has addressed different perspectives for defining road safety, the dynamics of a crash, and models for understanding and explaining crashes. In the next module we will continue to discuss road safety as a dynamic, complex, multidisciplinary, multimodal discipline. NCHRP 17-40, June 2010

Exercise #1 Defining Safety Imagine you are speaking with someone who just learning English and the person asks you what safety means. How would you define it for them? NCHRP 17-40, June 2010