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Research Brief

Key Findings

  1. A national approach to funding traffic crash intervention is less expensive than a state-specific approach, but it might not be as effective.
  2. The new, free-to-use tool, Motor Vehicle Prioritizing Interventions and Cost Calculator for States, can help decisionmakers measure the cost-effectiveness of traffic crash–intervention policies and programs in their states.

In the United States, each state is responsible for implementing policies to reduce vehicle crashes.[1] Policies can vary between states but often include measures to deter speeding, prevent driving while intoxicated (DWI), and increase the use of seat belts and motorcycle helmets. Supporting these policies is expensive; states pay millions of dollars each year for police time, equipment, and more. Thus, state policymakers must prioritize and choose the interventions that will provide the greatest reduction in injuries and deaths for their implementation dollars.

Given that most state budgets for traffic crash intervention policies are tight, it is worth asking this: Would it be more cost-effective for the country to implement the most effective national intervention across all states that lack it, or to have each state implement its most cost-effective intervention?

This research brief answers these questions with the data set used to develop the Motor Vehicle Prioritizing Interventions and Cost Calculator for States (MV PICCS). MV PICCS is a free-to-use tool to help policymakers prioritize and choose the traffic crash interventions that reduce the number of injuries and deaths for a given state budget. The RAND Corporation created MV PICCS with funding and technical support from the Centers for Disease Control and Prevention's (CDC's) National Center for Injury Prevention and Control and the Robert Wood Johnson Foundation. It is available at the CDC website:

Would it be more cost-effective for the country to implement the most effective national intervention across all states that lack it, or to have each state implement its most cost-effective intervention?

The Costs of Traffic Crashes: Lives, Well-Being, and Money

Traffic crashes remain a leading cause of death in the United States. We know that, in 2013, for example, they killed 32,719 Americans. And even when crash victims survive, they can find themselves negatively affected for a long time after: More than 2.3 million were injured in motor vehicle crashes in 2013. The direct and indirect costs of lives lost and harmed are typically higher than the millions of dollars the nation spends on prevention: In 2010, for example, crash-related costs reached about $242 billion.

How Cost-Effective Are Traffic Crash Interventions?

We conducted our analysis of costs and effectiveness on 11 interventions that have proven effective at saving lives and preventing injuries. We present them in Table 1. Cost refers to costs to the state for implementing an intervention; effectiveness refers to the number of lives saved and injuries prevented, as well as the estimated monetary value of saving a life and preventing an injury. These values include emergency and ongoing medical care and lost productivity and vary by state.

Table 1. Eleven Cost-Effective Traffic Crash Interventions

Photo by U.S. Department of Transportation/CC BY 2.0

Alcohol or ignition interlocks

Devices that prevent a vehicle from starting until the driver has blown into a tube to prove sobriety

Photo by Josh Kellogg /CC BY 2.0

License plate impoundment

Requires drivers convicted of driving while intoxicated (DWI) to surrender their vehicles' license plates

Photo by lzf/Fotolia

Primary seat belt–use laws

Allow police to ticket offenders exclusively for not wearing seat belts

Photo by trekandphoto/Fotolia

Automated speed camera enforcement

Cameras capture images of vehicles with drivers driving in excess of posted speed limits

Photo by carballo/Fotolia

Bicycle helmet laws

Mandate that children who ride bicycles wear helmets to reduce the likelihood of head trauma and related consequences

Photo by stockpics/Fotolia

Limits on DWI diversion and plea agreements

Prevent DWI arrestees from diverting cases or pleading out of charges

Photo by Photo: U.S. Nicholas Eckhart /CC BY 2.0

Automated red light enforcement

Cameras capture images of vehicles with drivers who fail to stop for red lights

Photo by ChiILLeica/CC BY 2.0

Vehicle impoundment

Requires that a DWI offender's vehicle be confiscated for a period of time, after which the offender either reclaims or surrenders his or her vehicle

Photo by Oleh Tokarev/Fotolia

In-person license renewal for older drivers

Requires all drivers over age 70 to renew their drivers' licenses in person rather than by mail or online

Photo by marino/Fotolia

Universal motorcycle helmet laws

Require all motorcyclists, regardless of age or experience level, to wear helmets that meet safety standards

Photo by Scott Liebenson/CC BY 2.0

Sobriety checkpoints

At specific locations, teams of police officers stop cars to check whether drivers are intoxicated

A National Approach to Funding Traffic Crash Interventions Is Relatively Inexpensive, but Not All States Benefit Equally

Table 2 presents the six most cost-effective traffic crash interventions out of the 11 that we considered. For each intervention, we calculated the costs and effectiveness only for those states that do not already have the intervention, and then we added up the costs and benefits for all those states. The results in Table 2 come from aggregating the costs and effectiveness across all states. Results are arranged in descending order by the cost-effectiveness ratio.

Table 2. Interventions Ranked Nationally, by Cost-Effectiveness

Intervention Number of States Without Intervention Lives Saved Injuries Prevented Cost to Implement ($) Benefit ($ value of lives saved and injuries) Cost-Effectiveness Ratio
Alcohol interlocks 12 93 3,352 1,426,000 185,348,000 129.9
Universal motorcycle helmet laws 30 745 197,019 41,000,000 5,020,486,000 122.4
License plate impoundment 34 382 13,814 12,397,000 823,687,000 66.4
In-person license renewal for older drivers 35 307 27,927 41,220,000 1,009,190,000 24.5
Bicycle helmet laws 26 38 6,587 7,998,000 184,965,000 23.1
Primary seat belt–use laws 16 302 31,876 53,793,000 1,064,900,000 19.8
Total   1,867 280,575 157,834,000 8,288,576,000 52.5

NOTE: We have rounded benefits and costs to the nearest 1,000. The totals and the cost-effectiveness ratios are based on the underlying numbers, so some slight inconsistencies are due to this rounding.

The results of this exercise suggest that increasing the use of alcohol interlocks on a national basis can save the most lives for the least cost. This policy alone could prevent 93 fatalities and 3,352 injuries in the first year of implementation. Implementing the policy costs $1.4 million. This is a relatively low cost for two reasons: Alcohol interlocks are fairly inexpensive for states, and only 12 states would need to adopt this policy. Implementing alcohol interlock laws in just these 12 states would ultimately save more than $185 million in crash-related costs.

The total effectiveness increases considerably if we add in universal motorcycle helmet laws in the 30 states that do not currently have them. This would save 745 lives and prevent nearly 200,000 injuries. This is almost as cost-effective as alcohol interlocks. The other four interventions have much lower cost-effectiveness ratios.

A State-by-State Approach Is More Effective but Can Cost More to Implement

We can compare that approach to one in which we fund the top-ranked intervention in each state. By top-ranked, we mean the most cost-effective intervention that is not already implemented. The top-ranked intervention varies from state to state, due to differences in state characteristics and the sets of interventions that are already in place.

Currently, 30 states lack universal motorcycle helmet laws; in 24 of those states, implementing universal motorcycle helmet laws would be the most cost-effective intervention. Such laws are relatively inexpensive to implement, and they are one of the most-effective interventions in terms of saving lives.

Moreover, states without these laws stand to benefit most because they have higher ratios of motorcycle fatalities. In 15 states, motorcycle deaths made up 15 percent or more of all vehicle crash deaths (the national average is about 13.5 percent); of these, only three have helmet laws already. Texas stands to benefit the most: A universal motorcycle helmet law could prevent 120 deaths and nearly 31,800 injuries in the first year after implementation. Across all 24 states where helmet laws are ranked first for cost-effectiveness ratios, 605 lives could be saved. An additional 140 lives would be saved in the other six states that do not currently have universal motorcycle helmet laws in place.

The map shows the top intervention for each state. Table 3 presents the costs and benefits of each intervention.

Table 3. Top-Ranked Interventions, by Number of States

Intervention Number of States Without Intervention Lives Saved Injuries Prevented Cost ($) Benefit ($) Cost-Effectiveness Ratio
Low Overall High
Universal motorcycle helmet laws 24 605 160,092 32,775,000 4,118,403,000 44.6 125.7 222.3
License plate impoundment 12 191 6,917 5,284,000 415,594,000 3.1 78.7 348.0
In-person license renewal for older drivers 8 49 4,464 14,290,000 157,421,000 0.4 11.0 232.8
Alcohol interlocks 5 66 2,371 592,000 130,665,000 12.2 220.7 390.0
Primary seat belt–use laws 1 13 1,367 6,490,000 55,187,000 n/a 8.5 n/a
Bicycle helmet laws 1 4 746 481,000 20,647,000 n/a 42.9 n/a
Total 51 928 175,957 59,912,000 4,897,917,000 0.4 81.8 348.0

NOTE: Benefits and costs are rounded to the nearest 1,000. n/a = not applicable.

Figure 1. Top Intervention for Each State

Map of United Shows showing the top intervention for each state

Whether to Fund Nationally or State by State Depends on Policy Goals

There is not a clear-cut one best way to allocate traffic safety money among the states. It is actually relatively cost-effective overall to implement the top-ranked intervention in each state: nearly $82 in benefit for every $1 spent. The federal government can save nearly double the number of lives if it implements the same six interventions in all states that lack them, but this costs $157 million, as opposed to $59 million. If the focus is on saving the greatest number of lives with a single intervention, the federal government would fund universal motorcycle helmet laws in the 30 states without them; this would save almost 750 lives and prevent 200,000 injuries for $41 million, or $122 in benefits for every $1 spent.

About the Motor Vehicle Prioritizing Interventions and Cost Calculator for States

MV PICCS brings together, in one place, a wealth of information on the costs and effects of 14 traffic crash interventions. Users can change a variety of parameters: the state, the interventions to analyze, the type of analysis (looking at each intervention individually or using "portfolio analysis" to account for related interventions), the use of fines and fees to offset costs, and the budget. A built-in sensitivity analysis tool allows changes to the percentage reduction in injuries and deaths, the estimated monetary value of saving a life, and the total cost per intervention.


  • [1] Our analysis included the District of Columbia along with the 50 states.
  • Development of the Motor Vehicle Prioritizing Interventions and Cost Calculator for States tool was funded by the CDC's National Center for Injury Prevention and Control, under contract 200-2011-39728.

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