Claire Mercer is calling for a judicial review to stop Highways England building more smart motorways, after her husband was killed three months ago.
Jason Mercer pulled over against the crash barrier to swap details with another driver following a minor collision.
The hard shoulder had been turned into a fourth lane. Jason and the other driver, died when they were hit by a lorry.
- Watch: Claire Mercer talks about the circumstances of her husband's death
The aim of smart motorways is to ease congestion.
There are currently 416 miles of smart motorways, including the M3, M25 and M23.
Highways England plans to increase this to 788 miles by 2025.
Warning signs on electronic gantries should indicate when a lane is closed and lay-bys on smart motorways are a mile and a half apart.
Despite this, smart motorways are considered unsafe by motoring organisations.
- Watch: Edmund King, AA President explain why he thinks smart motorways are unsafe
Sam Cockerill wants better safety measures to protect roadside recovery workers.
Her partner Steve was killed when he was struck by a lorry while responding to a breakdown on the hard shoulder of the M25.