Submissions close on SA road project

The South Australian and federal governments are set to close off public submissions on Adelaide's $620 million Darlington upgrade.

Design concepts for the road project were released last month with the public having until Wednesday to offer their views.

The Darlington upgrade aims to eliminate congestion with a 2.3-kilometre non-stop motorway along a section of Main South Road in Adelaide's southern suburbs.

Construction is due to start later this year and be completed by the end of 2018.