COBA

COBA is a Department for Transport sponsored computer program maintained and distributed by TRL. It estimates the effects of highway improvements, in terms of time, vehicle operating and accident costs on the users of the road system. These user cost changes are compared with the construction and maintenance costs over the appraisal period. Traffic flows with and without the scheme being appraised are input together with a detailed geometric description of the network links and junctions. The individual link and junction user costs are summed to yield the total costs over the network. COBA is suitable for the economic appraisal of highway schemes that are considered not to affect trip making behaviour, that is, a fixed trip matrix. It can also be used to assess the effect of schemes on accident costs for variable matrix appraisals that use alternative methods to estimate the economic effects.

A full copy of the COBA user manual is included on the software release disk. (The manual is Volume 13 of the Design Manual for Roads and Bridges (TSO).) The manual can also be viewed online at www.dft.gov.uk/strategy/coba

Further details of DfT's transport analysis guidance and programs and guidance from DfT

Dedicated COBA website

A website dedicated to COBA and QUADRO can be found at www.dft.gov.uk/cobaquadro. This website aims to facilitate the distribution of new releases of this software to customers by allowing existing licence holders to download the latest versions as they are made available. To do this each customer will shortly be sent a user name and password.

When a new release of either COBA 11 or QUADRO 4 is made available, existing licence holders will be informed by e-mail. To download the latest versions customers should log onto www.dft.gov.uk/cobaquadro/downloads.