RouteZero is aligned to the GHG Protocol's Technical Guidance, which recognises three primary methods: fuel-based, distance-based, and spend-based. Fuel-based methods are the most accurate and recommended when
- business travel contributes significantly to scope 3 emissions and
- data is available on the types and quantities of fuels consumed during travel.
Though this is rare for travel managed by third-party providers, RouteZero differentiates itself by working to collect the requisite data to enable the recommended approach by the GHG Protocol.
Distance-based calculations are the most commonly used for baselines, requiring records of all distances traveled by mode and multiplying by verified, mode-specific emission factors. Spend-based, applying emissions factors to financial data, is least precise and best suited when granular activity data is absent. A credible baseline prioritizes activity data, not financial proxies, wherever possible.
