The Handbook of Emission Factors for Road Transport

We will implement an update tonight on the HBEFA server to correct some errors identified in HBEFA 5.1 since its publication.

For details on the changes, please see: HBEFA5.1.002_Update_Dec2025.pdf

Since the changes are implemented on the server, HBEFA users do not have to download a fresh desktop client (front-end application) due to the update.

‍The update will be implemented tonight, i.e. on December 17, 2025, from 18:00 CET (likely for not more than 1 hour) on the central server. Several server restarts may be possible during that time.

A new version of the desktop client will be made available in the next days - with the only change being that the button to open the Help file has been moved to a separate "Help" menu in order to be found more easily. It is completely optional to download this new version. The content corrections on the server will also be effective with the desktop client used so far.

The free "online version" on this website will be updated in the next days to reflect the changes in the 5.1.002 update.

We are pleased to announce the release of HBEFA Version 5.1!

Registered and new users can obtain the new version by filling in the registration form on this website under SOFTWARE > GET THE HANDBOOK.

Version 5.1 is a major update. All contents of the Handbook have been updated. Version 5.1 represents a substantial extension of contents compared to previous versions, with additional pollutants, subsegments, and about five times as many base emission factors as in HBEFA 4.2. Furthermore, the new version is implemented as a user-friendlier Python-based client-server solution (as opposed to the previous MS Access-based versions).

An overview and documentation of the updated aspects is available under METHODOLOGY > REPORTS > “HBEFA 5.1 Update Documentation”

Please see the updated help file on this website under SOFTWARE > VERSIONS >HBEFA 5.1 for a quick start with the new application.

Unfortunately, the French country data inputs are slightly delayed. They will be updated in a few days. Since the new application is a client-server solution, it will not need to be downloaded or installed afresh after the update. For the moment, it is just not possible to calculate results weighted with a fleet composition for France.

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