Why drivers fuel off-network, and what closes the gap.

The four causes

Ask why a fill happened outside the network and the honest answers fall into four groups. Which of them dominates your fleet is an empirical question, and your own card export answers it — the method is at the end of this page.

• The stop was too far off the route

  A detour burns fuel and burns hours against a clock the driver cannot extend. Past some distance the discount costs more to reach than it returns.

• The in-network stop was not actually cheaper

  A discount applies to a posted price, and posted prices differ between sites. The station with the bigger deduction can settle above the one with the smaller deduction off a lower sign, and neither number is visible from the cab.

• Stopping again was worse than filling here

  A driver facing two stops — a partial fill now, a network site later — has an obvious reason to take one. Every stop costs time the day does not give back. This is the one cause where the fleet's interest and the driver's genuinely conflict rather than differing in information, which is why it is the one that does not yield to telling the driver more.

• The tank had already decided

  By the time the tank is low enough, there is no decision left to take. Whatever is at the next exit is the stop, and nothing upstream can hand the choice back.

The first two are the planning problems the operator's guide works through in order: how to run a fuel program at a trucking company.

Why the usual remedies only reach half of it

The two things reached for first are better network coverage and tighter card controls. Both are real, and both are worth doing: coverage is the right conversation to have with your provider, and a card control stops a category of spend that nothing else stops.

But both act on the first two causes. A card control can refuse a transaction. It cannot give a driver back the time a second stop costs, and it cannot un-empty a tank. A fleet that has done both and still has off-network volume is looking at the third cause or the fourth, and those are not enforcement problems — the third is a planning problem and the fourth is a deadline problem.

This is the practical reason compliance campaigns underdeliver. They are aimed at a population that is partly structural, and the structural part does not respond to being asked more firmly.

Telling which of the four you have

The off-network rows in your card export carry the station, the lane, the date and the gallons, and that is enough to separate the four without asking anyone.

Plot those rows against your lanes and your provider's site list. Fills clustered where the site list is empty are the distance cause. Fills close to an in-network site are the price cause, or a driver who had no way to tell the two apart. Small fills at convenient stations are top-offs, which belong to the planning side. Large fills at whatever came next, after a long run with nothing taken, are the deadline cause.

Count them in gallons rather than in transactions. The deadline cause produces large fills and the top-off produces small ones, so counting rows flattens the distinction you are trying to draw.

For the denominator question and how to derive the rate itself: what a fuel compliance rate is, and how to calculate one.

Questions

Is an off-network fill always the wrong call?

No, and treating it that way costs you the number's credibility. A stop far off-route, or one that settles higher than a nearby alternative, is one the fleet should want skipped. A measure that counts every off-network fill as a failure teaches people to argue with it rather than act on it.

Will a card limit fix this?

It fixes part of it. A control addresses the first two causes and leaves the other two untouched, and it introduces a consequence of its own: some of those refused transactions become a driver with no authorised option and a tank that is still empty, which is a worse outcome than the fill was.

We fixed our network coverage and the number barely moved. What now?

Then the volume was not where the coverage was. Run the diagnostic above before doing anything else: if the remaining fills sit near in-network sites it is a price or information problem, and if they are large fills after long runs it is the deadline, which no amount of coverage reaches.