My experience as a not infrequent off peak traveller on BS 1 is that no increase in off peak frequency is justified. I can't comment on peak loadings. However a PVR increase of 5 suggests a 10 minute frequency.Ah, so is the 1 getting extra peak journeys? Or even an enhanced off-peak frequency (every 10 mins)?
One thing that would be nice is to be able to maintain the 15-min off-peak frequency in the peak. For example morning peak arrivals at Southampton are 0815-0840-0905 at the terminus, or around 0810-0835-0900 in the northern part of the city centre.
Five extra buses sounds like a likely significant frequency enhancement: I'd expect only around two vehicles to be needed to maintain off-peak frequency in the busiest peak hour.
Looks like there are currently 9 all-day vehicle duties, with a tenth in the morning peak heading into Winchester (https://bustimes.org/vehicles/blus-1797?date=2025-06-19) which then does other things in the afternoon. So five extra vehicles is an approximately 50% enhancement.
However Hampshire CC, who have just decided not to renew the tender of my local route, appear to have decided to spend some of their precious BSIP money on a frequency increase, no doubt encouraged by GSC.
Unimpressed of semi-rural Hampshire........