How does vehicle tracking calculate and use driver scores?

Every fleet manager, no matter the size of their fleet, is concerned with improving driver performance. Whether it’s to mitigate the risk of accident or reduce fuel costs, it has become the standard for fleets to monitor and correct driving behaviors. The data collected by a vehicle tracking system is a rich source of information on a driver’s personal performance.   

Quartix provides an easy-to-understand, color-coded score for each vehicle or driver in a fleet.  This score features prominently in Quartix’s driving style reports as a way for fleet managers to instantly recognize which drivers need to improve their skills.   

This score is calculated by looking at two important areas of driver performance.  

Acceleration and braking

The Quartix system monitors the speed of a vehicle every second. The system then calculates:  

• The number of times per hour that the speed changes by more than a given amount between one second and the next; 
• How severe the changes are; 
• How long the vehicle has been driving. 

This calculation becomes the acceleration index and the braking index. 

Acceleration index:  the sum of all the acceleration incidents, each multiplied by their severity and finally divided by the driving time in hours. Calculating it in this way means that no drivers are penalized for driving more or less than any other driver. 

Braking index:  the sum of all braking incidents, worked out in a similar way, except that the levels of speed change are slightly different, as are the severity weightings, as excessive braking is considered to be more of a risk factor. 

There are 10 levels of acceleration and braking and each level has a weight based on its severity. For example, if a vehicle’s speed increases by 6 mph in a second, that is a level 3 acceleration. If the speed decreases by 9 mph, that is a level 3 braking, and so on. 

Calculating the driver score

To get the driving style score, the Quartix system:  

• Adds up all the weighted acceleration and braking events; 
• Factors in vehicle speed; 
• Calculates the total driving time; 
• Works out the acceleration and braking indexes; 
• Averages these and subtracts from 100. 

This is the driving style score.  

For example, if you have a driver with an acceleration index of 10 and a braking index of 6, the average for this driver would be 8. This drivers’ driving score would be 100 minus 8, equalling a score of 92. 

Our system calculates the driver score each day based on the amount of driving for that day or shift. We apply colors to the scores, as well, for easy identification.  

GREEN:  Scores greater than 80, representing the best 30% of drivers. 

AMBER:  Scores between 50 and 80, representing the middle 50% of scores. 

RED:  50 and below, representing the worst 20%. 

“When we first started using the Quartix driving style tables and sending them out to the managers, it immediately started an improvement in driving style, less harsh breaking or acceleration.”

Driving style reports

The best place to see an individual vehicle or driver’s performance is the daily driver briefing, a report that summarizes both the speed and driving style scores for the day, as well as driving and idling times. It’s a complete picture of the day’s driving performance, with the ability to click and view on a map any instances of high speed or harsh braking/acceleration. 

For comparing vehicles and drivers across a fleet, the driving style league table is a valuable tool that allows a fleet manager to easily spot drivers with low speed and driving style scores. Many businesses find this helpful to motivate their drivers into improving their driving performance. 

“With the driving style monitoring suite, we are able to identify problematic drivers and issues which need addressing. For the past 12 months, we have been incentivizing good driving by giving our drivers a retrospective bonus based on the data provided by the Quartix system.” – Darren Hammond, Director, C and D Southwest 

“We’ve seen around a 20% improvement in driving style across the fleet. Since using Quartix, our drivers are now in the 80-100 driving score range, which is where we wanted to be. We’re doing daily briefings with the drivers and they can easily see how their driving style has improved. Our drivers have faith in the Quartix tracking system. The driving style performance data makes sense to them and we’ve seen dramatic improvements in their scores as a result.” – Karl Davidson, Depot and Transport Manager, St. Austell Brewery 

Additionally, our fuel-efficient driving tips infographic can be handed to drivers, to help encourage more economical driving behaviors.

Seeing the benefits

Driving style scores are a way to clearly identify driving behaviors that should be corrected, making it easier to effect changes in line with specific goals, like reducing costs and increasing road safety.  It won’t happen overnight, but the benefits far outweigh the effort of laying the foundations of change.  

For examples of how Quartix clients have used vehicle tracking and driving style reports, read more of our case studies.