function calculateSafetyRate() {
// 1. Get input values
var accidentsInput = document.getElementById('totalAccidents');
var milesInput = document.getElementById('totalMiles');
var vehiclesInput = document.getElementById('totalVehicles');
var accidents = parseFloat(accidentsInput.value);
var miles = parseFloat(milesInput.value);
var vehicles = parseFloat(vehiclesInput.value);
// 2. Validate inputs
if (isNaN(accidents) || accidents < 0) {
alert("Please enter a valid number of accidents.");
return;
}
if (isNaN(miles) || miles 0) {
ratePerVehicle = accidents / vehicles;
hasVehicles = true;
}
// 4. Display Results
document.getElementById('result-box').style.display = 'block';
document.getElementById('apmmDisplay').innerText = ratePerMillion.toFixed(2);
document.getElementById('per100kDisplay').innerText = ratePer100k.toFixed(2);
if (hasVehicles) {
document.getElementById('perVehicleDisplay').innerText = ratePerVehicle.toFixed(3);
document.getElementById('vehicleRow').style.display = 'flex';
} else {
document.getElementById('vehicleRow').style.display = 'none';
}
// 5. Determine Rating (General industry benchmarks for fleet safety)
// Note: These benchmarks vary by industry (Trucking vs Sales Fleet), but general logic applies.
var ratingText = "";
var ratingColor = "";
if (ratePerMillion === 0) {
ratingText = "Perfect Record";
ratingColor = "#28a745"; // Green
} else if (ratePerMillion < 1.0) {
ratingText = "Excellent";
ratingColor = "#28a745"; // Green
} else if (ratePerMillion < 2.5) {
ratingText = "Average / Acceptable";
ratingColor = "#ffc107"; // Yellow/Orange
} else {
ratingText = "Needs Improvement";
ratingColor = "#dc3545"; // Red
}
var ratingElement = document.getElementById('ratingDisplay');
ratingElement.innerText = ratingText;
ratingElement.style.color = ratingColor;
}
Understanding Motor Vehicle Accident Rates
For fleet managers, safety officers, and transportation logistics coordinators, tracking the Motor Vehicle Accident Rate is crucial for assessing risk and maintaining Department of Transportation (DOT) compliance. This metric provides a standardized way to compare safety performance across different time periods or against industry benchmarks, regardless of fleet size or miles traveled.
How to Calculate Accident Rate (APMM)
The most common industry standard for measuring fleet safety is Accidents Per Million Miles (APMM). This formula normalizes the data, allowing a fair comparison between a fleet that drives 100,000 miles a year and one that drives 10,000,000 miles a year.
Accident Rate = (Number of Accidents × 1,000,000) ÷ Total Miles Driven
Example Calculation:
If your fleet experienced 3 accidents over the course of a year, and the total mileage for all vehicles combined was 1,500,000 miles:
(3 × 1,000,000) = 3,000,000
3,000,000 ÷ 1,500,000 = 2.0 APMM
Why Tracking This Metric Matters
Benchmarking: It allows you to compare your safety record against national averages (e.g., the FMCSA averages for trucking).
Insurance Costs: Lower accident rates often correlate with reduced insurance premiums and liability exposure.
Preventable vs. Non-Preventable: Many fleets run this calculation twice: once for total accidents and once specifically for "preventable" accidents to measure driver performance more accurately.
Interpreting Your Results
While benchmarks vary significantly by industry (e.g., long-haul trucking vs. local delivery vs. passenger transport), generally lower is better. An APMM of 0.0 is the ultimate goal. Rates consistently above industry averages indicate a need for enhanced driver training, stricter safety policies, or vehicle maintenance reviews.
Additionally, looking at the Accidents Per Vehicle metric (also provided in the calculator above) helps identify if the issue is widespread or isolated to specific high-utilization assets.