Dynamic integrated assignment and demand modelling
DIADEM (Dynamic Integrated Assignment and DEmand Modelling) is a software tool maintained and supported by Atkins Limited on behalf of the Department for Transport.
The purpose of DIADEM is to enable users to easily set-up variable demand models in accordance with the advice provided in WebTAG, specifically TAG unit M2 variable demand modelling.
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. DIADEM is principally used in conjunction with SATURN but the CONTRAM package may also be used. The current DIADEM release is version 5.0 (February 2011).
Current licence holders can download the DIADEM release and updates using their user ID and password.
All prices exclude VAT, which will be applied at the prevailing rate where appropriate.
|Type of use
||Licence fee (£)
|Commercial use within the EU
|Educational use within the EU
|Commercial use World Licence (including use outside the EU)
|Educational use World Licence (including use outside the EU)
VAT at prevailing rates will be added to the above prices where appropriate.
The licence entitles the user (subject to the the Licence Agreement) to use of the software for an unlimited period of time and, within 12 months of purchasing the licence, user support and access to download new versions of the software from this site. Full details are given in the licence agreement.
One licence entitles a user to install multiple copies of DIADEM but at a single site. Additional copies may be purchased at the same prices for additional sites – there is no discount available for additional copies.
The prices are agreed with DfT and cannot be negotiated.
Licences purchased for educational use may be used by students for the purpose of gaining educational qualifications. Research institutions (eg universities) must purchase a commercial licence in order to use the software to carry out research for payment. local authorities must also purchase a commercial licence to use the software.
Commercial EU licences can only be used for appraising transport schemes within the EU. Appraisal of transport schemes outside the EU may only be undertaken with a commercial world licence.
There are 3 payment options (non-UK orders must use the third option) which include:
- sending us an official purchase order - receipt of this we will despatch the software immediately and issue you with an invoice which must be paid within 30 days
- sending us a cheque for the full amount, including VAT (if applicable), made payable to Atkins Limited, to Ian Wright at the address below - on receipt of your cheque we will despatch the software immediately and issue you with an invoice for your records
- asking us to issue an invoice - the software will be despatched when full payment has been received
Epsom Gateway (1st Floor)
Surrey KT18 5BW
Telephone: +44 (0) 1372 756755
When placing an order please let us know your full contact details, ie name, organisation, address, telephone number and email address. Please also let us know the site address(es) at which the software will be installed
If you have any questions, problems or suggestions please contact the DIADEM help desk at Atkins Limited: firstname.lastname@example.org. All feedback on DIADEM is very welcome.
Guidance on all aspects of transport modelling, including assignment and variable demand modelling, can be found on WebTAG.
General enquiries about WebTAG, variable demand modelling and the interpretation of the guidance should be directed to TASM division at the Department for Transport: email@example.com.