Standards
Editorial policy
This policy describes the standards used for RoadCost’s calculators, guides and trust pages. It is deliberately narrower than a general newsroom policy: this site publishes calculations and explanatory content, not current affairs or product reviews.
Topic selection
A page must address a distinct user need. Calculator, converter, online, free, spelling and formatting variants are treated as one intent unless there is evidence that they require genuinely different information. We do not create a page per number, year, country name or keyword permutation.
Changing rules and prices are held back until they can be verified against an official source and maintained. A useful calculator with transparent inputs is preferable to a page that presents an invented “current” price.
Sourcing
- Unit definitions and constants come from standards bodies or official definitions.
- Fuel-economy labels and MPGe context come from EPA / fueleconomy.gov sources.
- Price context, where cited, comes from official statistical or regulatory sources.
- Where a source is not official, it is described as context rather than authority.
- We do not invent search volumes, competition scores, reviews, quotes or regulations.
Calculations and verification
Formulas live in a central calculation library. The site shows the formula, the units and the assumptions on the relevant page. Automated tests cover normal inputs, boundary cases and invalid inputs. A passing test proves the implementation matches the documented formula; it does not prove that a market price or regulation is current.
Changing figures are not hardcoded into the calculators. Fuel prices, electricity prices and vehicle efficiency are user inputs. Where a future page depends on an official rate, the page must show a source link and a last-verified date.
What a last-reviewed date means
Estimates versus official rules
A calculated result is an estimate based on the inputs. An official rule is a statement from an authority. The site keeps the two separate. We do not label an estimate “official”, and we do not present an official rule as if it were a calculation.
Corrections and updates
Corrections are logged on the corrections page. A correction should identify the page, the error, the correct information and a source. When a factual error is found, the page is updated and the review date is changed. We do not silently change a year or a price to make a page look fresh.
Pages are reviewed when a formula, source or unit definition changes. Time-sensitive data is not published until a maintenance process exists.
Independence and advertising
The site is not affiliated with any government, manufacturer, charging network, fuel retailer or toll authority. Commercial relationships, if added, must not determine a calculation result or a factual statement.
No advertising is enabled in this build. If advertising is added, it must be labelled, kept separate from calculator controls, and must not obscure results, cause accidental clicks or be disguised as part of the tool. EEA/UK consent requirements will be implemented before any advertising cookies are used.
AI assistance
This build was assembled with AI assistance. That is disclosed rather than hidden behind invented credentials. Formulas are tested, sources are cited, and limitations are documented. The project does not claim professional engineering, legal, tax or financial expertise.
Page last reviewed: . Formulas are covered by automated tests. Prices are inputs, not live data.