The Handbook of Emission Factors for Road Transport

The guidelines have been developed to

- promote consistent application of the HBEFA Traffic Situation between users and use cases

- to make methods and experiences developed over time available to all HBEFA users

- and to save users time.

The Guidelines are available on the website of the German Environment Agency (UBA-DE): www.umweltbundesamt.de/publikationen/hbefa-traffic-situations

We have decided today to move the publication of HBEFA 5.1 to October 2025.

The beta tests have been concluded by end of August. We have received very positive feedback. A few bugs have been identified that we are going to fix in the coming days.

The most important reason for postponing the publication date is that the general level of the new non-exhaust emission factors has been questioned - an issue that we want to investigate further before we publish the new version.

We are pleased to announce that we are planning to release HBEFA 5.1 in September 2025.

HBEFA 5.1 is a major update.

New features - besides a general update of all contents based on the latest measurement and statistical data - include e.g. non-exhaust emission factors differentiated by detailed vehicle types and processes, new cold start emission factors (also for HDV and BEVs), new and more detailed vehicle types (L-category, HGV size classes), Euro-7 emission factors and more.

HBEFA 5.1 will be released on a new software platform, as a Python-based client-server solution - as opposed to the Microsoft Access platform used up to Version 4.2.

License prices will be increased by 40% to compensate for inflation since 2010, when the current prices were introduced.