A man, the fourth person injured, was also taken to hospital, after being arrested on suspicion of dangerous driving and failing to stop.
He was detained after a Volkswagen Golf, BMW and a van were all found fully engulfed by flames, when crews arrived, West Midlands Fire Service said.
Disruption to services, also affecting Avanti West Coast and Transport for Wales, was expected to last until about 17:00, National Rail said.
Many trains were left stranded as a result of the fire and services between Shrewsbury and Wolverhampton would be covered by rail replacement services, West Midlands Railway said.
Rail tickets can also be used with Metro tram and National Express coach services, it added.
London Northwestern Railway said the fire had led to a lack of trains to cover the Potteries – Crewe to Stafford via Stoke-on-Trent – and replacement services would be also put in place.
