MTO initiated the Preliminary Design Study in 2001 to identify required improvements and widening requirements along 30 km of Highway 400 from 1 km south of Highway 89 to the Junction of Highway 11 (GWP 30-95-00). A Transportation Environmental Study Report (TESR) received Environmental Clearance to proceed to further stages of design in 2006.

In 2014 MTO initiated an Update to the Preliminary Design Study and Approved Environmental Assessment previously completed.  The objective of the 2014 study was to review the present (2013), short term (2021) and long term (2031) planning horizons.  in addition, the study update examined transportation problems, opportunities and issues relating to the existing interchanges within the 30 km Highway 400 study area.  In 2017 a TESR Addendum received EA approval. The Addendum updated the project, incorporated future (2031) traffic projections, and addressed associated capacity, operational and safety needs.

The TESR Addendum is provided under the Documentation section.