The Verdict
For city centre guests catching early trains, the Radisson Blu at Holloway Circus is the clearest answer. New Street is seven minutes on flat ground, there are no hills, no complicated road crossings, and no need to factor in a taxi. For a hotel of this category, that walk-time to a major rail hub is genuinely hard to beat in Birmingham.
For budget travellers departing early, the Holiday Inn Birmingham City Centre sits four minutes from New Street and costs considerably less than the Radisson Blu for comparable proximity. It will not win on atmosphere, but at 4am with a bag and a train to catch, atmosphere is irrelevant. The Premier Inn on Bridge Street is a reasonable alternative for those whose departure involves New Street or Five Ways, though it adds two or three minutes to the walk and is better suited to those who used Broad Street the night before.
For drivers leaving Birmingham early and bypassing the city centre entirely, the Greenland's Inn at Longbridge is the specialist pick. It sits outside the Clean Air Zone, offers free on-site parking, and puts the M42 and A38 within straightforward reach without touching the inner ring road. It is not a base for exploring Birmingham, and should not be treated as one, but for an early motorway departure after a south Birmingham appointment or event, nothing else on this page comes close.