Downloading LinSig 3.2.39 from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this software available. The most popular version among LinSig users is 3.2. The actual developer of the software is JCT Consultancy Ltd.
LinSig lies within Photo & Graphics Tools, more precisely 3D Design. According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. Commonly, this program's installer has the following filename: Linsig.exe.
From the developer:
LinSig is a computer software package for the assessment and design of traffic signal junctions either individually or as a network comprised of a number of junctions. It is used by traffic engineers to construct a model of the junction or network which can then be used to assess different designs and methods of operation.
You may want to check out more software, such as Win4D Advance or FRED Optical Engineering Software, which might be similar to LinSig.