New Service 378 was introduced by Birmingham and Midland Motor Omnibus Company Limited (BMMO—Midland “Red” Motor Services) on Sunday 19th May 1929, running between Great Malvern, Malvern Wells and Upper Welland (Marl Bank). The service ran during the summer season with three return journeys on Sundays only.
On Monday 7th January 1935, local Malvern services were renumbered with “M”-prefix route numbers. Service 378 was not considered a local service so was not included at this time, but the company later changed its mind and Service 378 was renumbered into the local Malvern sequence as Service M28 on Sunday 3rd July 1938, halfway through the 1938 season.
Route number 378 was reused within weeks for a Saturday-only services running between Worcester, Broadheath and Martley Hillside, as a short-working variation to new Service 410.
After being renumbered to Service M28, the service operated for the remainder of the 1938 season and the 1939 season before being withdrawn in September 1939, due to fuel rationing introduced following the outbreak of the Second World War.
1 Service 378 ran only on Sundays during the Summer Season.
| 3 | 7 | 8 |
| April | 1933 | Great Malvern ↔ Upper Welland ↔ Welland | |
| May | 1938 | Great Malvern ↔ Upper Welland ↔ Welland |
Route number 378 was reused in the Malvern area from Monday 20th September 1943 for a service linking Worcester with the Radar Research and Development Establishment (RRDE) on Leigh Sinton Road, and the Telecommunications Research Establishment (TRE) on St. Andrews Road in Malvern.
Service 378 operated six days a week, with no service being offered on Saturdays, and was not advertised in the timetable books that were sold to the general public. This service was withdrawn on Friday 10th January 1958.