Road Safety and Risk Estimation Quiz

Estimating Risk and Exposure in Road Accidents

• Exposure in risk analysis includes person-kilometers of travel, number of trips, time spent in traffic, driver population, and population.
• Per capita and licensed drivers are basic measures of exposure, expressed per thousand or per million people.
• Registered vehicles and vehicle-kilometer traveled (VKT) are common measures of exposure for computing and comparing crash rates over time.
• Annual average daily traffic (AADT) and segment crash rate are used for measuring crash risk for a single site like an intersection or roadway segment.
• Crash rates assume a linear relationship between crash frequency and exposure, but studies have shown it is often nonlinear.
• Traffic conflicts and surrogate safety measures, such as time to collision (TTC) and post encroachment time (PET), correlate well with actual crashes.
• Road trauma cost the Australian economy nearly $30 billion in 2015, equivalent to 1.3% of GDP.
• The total social cost of road crashes in Australia for 2016 was $33.16 billion, equating to 2% of GDP.
• The value of a statistical life (VSL) is an economic concept used to estimate the monetary value associated with reducing the risk of a premature death.
• VSL is estimated to be about $4.1 million and is used to determine the cost of road fatalities in Australia, which was about $5 billion in 2015.
• Estimating the costs of road accidents is essential for evaluating the benefits of road safety measures and for internalizing various economic costs to influence road user behavior.
• The value of risk reduction measures how much society is willing to pay in addition to the summary of health care costs, gross lost production, cost of property damage, and administration for improved traffic safety.