Freight Fuel Surcharge Index Governance: Pegs, Lags and Invoice Audits

What should an awarded fuel surcharge schedule fix?

In truckload contract markets, according to a 2025 peer-reviewed study of fuel cost pass-through, base rates exclude fuel, a separate surcharge follows a benchmark such as an EIA index, and agreements are often set a year before fuel prices are known. In the same study, the shipper therefore bears the fuel price risk, paying the surcharge in force when the load is tendered.

Bid-stage questions, including what the EIA weekly series measures and where it stops, are covered in the method for making freight-lane bids comparable, which this guide does not repeat. In this guide's view, the signed schedule needs seven terms: peg, step and rounding, efficiency constant or percentage table, index week and geography, missing-release rule, charge base, and audit and dispute rules.

How should the peg relate to the linehaul rate?

In the 2025 study's account of contract pricing, contract language separates base rates from fuel costs, yet in practice rates and surcharges are jointly determined. According to the Surface Transportation Board's 2007 reporting rule, one commenter asked for data on misaligned surcharge thresholds, where the surcharge's base fuel price sits below the fuel cost in the rail rate, so the carrier double-dips; the Board did not add that item.

According to a 2012 peer-reviewed case study in Interfaces, a large US shipper saw an unexpected jump in fuel surcharges when diesel prices spiked in summer 2008. In that case study, a lane assignment tool then let it weigh base price against risk-adjusted fuel surcharge, negotiate surcharge limits that share diesel price risk and better align surcharges with the true cost of diesel.

In this guide's view, ask each carrier which fuel price its linehaul already assumes, then set the peg at that level or reprice the linehaul when the peg moves. If the linehaul also escalates by an index that contains fuel, apply the rules for an auditable contract escalation clause so that one fuel move is not paid twice.

How should steps and the efficiency constant be written?

According to the Surface Transportation Board's 2019 safe-harbor notice, the Board found in 2007 that rate-based surcharges on regulated rail traffic, with no real correlation to the movement's added fuel cost, were an unreasonable practice, and it prohibited surcharges set as a percentage of the base rate. In the same notice, regulated rail surcharge programs must rest on movement attributes, such as mileage, that directly affect the fuel consumed.

Under the Board's 2007 reporting rule, that ruling applies only to regulated rail traffic, so it does not govern a truckload or less-than-truckload contract. In this guide's view, its test still helps: a percentage-of-linehaul table moves with the rate, not with miles or gallons, so record why a lane uses one and recheck it when linehaul rates change.

Fuel use per mile varies: in the 2025 study, route, equipment configuration, cargo weight, vehicle fuel economy, elevation and traffic all shape consumption, and the authors' per-mile estimates are sensitive to the fuel efficiency they assumed. In this guide's view, write the efficiency constant as a dated term per equipment type and review it on a fixed date.

Under EIA's published methodology, each weekly average price has an estimated standard error in a separate report, and an estimate is flagged when its coefficient of variation exceeds 5%. In this guide's view, check the published standard error before choosing a narrow step, and state the step width, rounding and whether the table moves the same way up and down.

Which index week and region should an invoice use?

According to EIA's survey method, prices are collected as of 8:00 a.m. local time on Monday and published around 10:00 a.m. ET on Tuesday, or on Wednesday after a government holiday while still representing Monday's prices. Under the same method, EIA publishes national, regional and California averages.

In EIA's release of November 10, 2026, the week of 11/09/26 shows 6.127 dollars per gallon for the U.S., 5.741 for the Gulf Coast and 7.110 for the West Coast. In this guide's view, name the series and geography, tie the index week to one shipment date such as tender or pickup, and state when each value takes effect.

In this guide's view, date every schedule input, applying the discipline of checking freight forecast editions and their assumptions to the contract, so an auditor can trace each invoice's inputs.

What should happen when a weekly diesel price is late or missing?

Under EIA's methodology, prices for outlets that cannot be reached are imputed, and an average is withheld when at least half of the weighted annual sales volume rests on imputed prices. In June 2022, according to a Land Line news report, hardware-related system errors delayed EIA's releases for the week of June 20, including weekly diesel prices, and EIA planned to release the delayed data as soon as possible.

In this guide's view, state which value applies when a week's figure is late or withheld (for example, the last published week), whether a later release triggers a true-up, and which substitute applies if the series is discontinued or renamed. Apply the rule the same way whether prices rose or fell.

How should fuel surcharge invoices be audited and disputed?

In a 2013 rail complaint recounted in the Surface Transportation Board's 2019 notice, BNSF's surcharge revenue over five years exceeded its incremental fuel costs by $181 million measured by what it actually paid for fuel, but not measured by the safe-harbor index, and the complaint was dismissed. In this guide's view, the contract should define what counts as correct and keep any comparison with actual fuel use as a separate review.

Under the Board's 2007 rule on fuel surcharge reporting, Class I railroads report fuel cost, gallons consumed, the change in fuel cost and surcharge revenue each quarter, counting revenue billed rather than collected. In the same rule, aggregated data serve as a monitoring tool, not a substitute for evidence in an individual case. In this guide's view, a buyer can mirror that by comparing each lane's surcharge billed with the fuel implied by miles and the constant.

In the 2009 edition of Title 49 of the US Code, a motor carrier must give a shipper, on request, the rate, rules and practices behind its rate, and each side faces a 180-day limit: a carrier to bill extra charges, a shipper to contest a bill. Under section 14101 of that edition, contract parties may expressly waive these rights in writing, and breach claims go to court unless they agree otherwise.

In this guide's view, write the audit and dispute rules into the schedule: the fields each invoice must carry, the recalculation tolerance, the dispute window and who decides. Ask counsel to confirm the current statute and any waiver before relying on a deadline.

Which terms should the surcharge schedule record?

The register below is this guide's proposal; every value it asks for is the parties' contract term, not a market norm.

How do AI agents change fuel surcharge audits?