A 25-year-old man died after the early-hours crash which involved a black Peugeot 207 and a HGV near Lichfield.
The crash happened on the eastbound carriageway of the A5 between Muckley Corner and Wall at around 12.25am on Saturday.
The man was pronounced dead at the scene.
A 41-year-old man from Walsall was arrested on suspicion of causing death by dangerous driving and a 37-year-old woman, also from Walsall, was arrested on suspicion of perverting the course of justice.
Both have since been released under investigation pending further inquiries.
Murray MacGregor, spokesman for West Midlands Ambulance Service, said: "We were called at 12.28am to reports of a male pedestrian in collision with a van.
"A paramedic officer attended the scene, unfortunately it was immediately obvious nothing could be done to save the man and he was confirmed dead at the scene."
Anyone who witnessed the collision, has dash-cam footage or may have seen anyone walking on the road between Wall and Muckley Corner is asked to call 101 quoting incident number 19 of November 16.