DIADEM is variable demand transport modelling software developed by Mott MacDonald on behalf of the Department for Transport. It stands for Dynamic Integrated Assignment and DEmand Modelling.

The purpose of DIADEM is to provide a straightforward way to implement a variable demand model consistent with Units 3.10.1 to 3.10.4 of the WebTAG guidance .

The main demand model used in DIADEM is an incremental hierarchical logit model of the following demand responses:

• Trip frequency
• Time period choice
• Mode choice
• Destination choice/distribution

Travel times and other costs are provided by a third party traffic assignment model. Currently DIADEM can be used with the CONTRAM and SATURN packages.

DIADEM is also designed to achieve convergence between supply and demand, as specified in WebTAG Unit 3.10.4 .

For more information about the technical details behind DIADEM please download the user manual or contact us if you have a specific question.

The current version of DIADEM is 5.0:

• DIADEM engine v5.0.4
• DIADEM GUI v5.0.5

Download

Different versions of the user manuals are available depending on whether you use SATURN or CONTRAM.

• DIADEM release notes 3.1 (PDF – 38 KB)
• DIADEM user manual 5.0 F CON (PDF – 1125 KB)
• DIADEM user manual 5.0 F SAT (PDF – 1167 KB)

DIADEM licence holders can download updates using their user id and password.

• Current DIADEM release: Version 5.0