Reading through the Traffic Commissioner's Notices & Proceedings (a wonderful archaic name, still in use today by the way) linked above it seems that operators had to seek permission to reduce or withdraw services.
I wonder if permission was given automatically or whether TC's had to consider whether hardship would be caused as was the case when closing railway lines or stations.
Reducing (or increasing, or changing times) services operators had to apply for, and could be objected to. The operator had to make a case, although if no objections were made this would be somewhat cursorily. The TC would consider the hardship of the objectors, but also the financial hardship of the operator. From about 1970 onward [and earlier in respect of some operators], the operators had little difficulty in showing their hardships.
Operators could 'surrender' a licence for a particular route (i.e. withdraw it completely) without any right of objection, although this was fairly rarely done until 1970s. Relations between the bus companies and the TC tended to be one of 'in exchange for a monopoly, we won't rock the boat' . When the bus companies balance sheets all turned red around 1970 then the boat had to be rocked, but it was too late.
Changes to licence particulars were only published in 'Notices and Proceedings', not so easily obtainable in the pre-digital age, so objections by individuals were fairly few. Local authorities often objected to fares increase applications as a matter of course, much to the chagrin of operators, whilst simultaneously objecting to service cuts and voicing their (adverse) opinions on one man operation and busman's wages! The TC's were independent and tried to steer a compromise route through all of this. People now look back and complain that the bus companies were slow to react at that time. Not surprising really.
