"Why is a double decker running around my town / village with very few people on it? Isn't that wasteful? Wouldn't it be better to use minibuses or taxis?" Good questions - asked of me in multiple community areas, including my 'home' area of Melksham. So here's an answer - feedback of the sort of thing I've been doing for years via www.passenger.chat and would do on local matters if elected to Town Council.

Answer / explanations

1. Could buses be switched around?

Buses run on "diagrams" - back and forth all day, some on the same repeated journey and some on different routes through the day. There will be busier times (travel to work, travel to education, just after 09:30 when senior cards become valid) and quieter times when these don't apply. There will also be busier and quieter sections of routes too; a really good example quoted to me is the X5 Swindon to Salisbury bus which loads well at the route ends for a double decker, but is quieter in the middle.

The bus used on a diagram needs to have enough capacity for its busiest time, and for the busiest part of its route. Observers not around at that time, or on the busiest part of the route, will never see a full bus and will ask the "do we need such a big bus" question; the answer is really "yes, for what else it is doing on the diagram".

Another suggestion made has been to have big buses for the peaks, and smaller vehicles off peak. The cost of extra vehicles is very high, and the time taken to get back to depot and switch a significant overhead. Switching vehicles between routes can sometimes provide a little help, but peaks loadings tend to happen at the same time of day on all routes. There are times where switching a vehicle that's run during the day on one route to another route in the evening helps, but even there a quiet mid-evening can be followed by a crammed late service. Even before CoVID social distancing, the 23:20 Bath to Melksham and Devizes really needed (but did not get) a double decker.

The question has also been asked about splitting routes. Running (say) a double decker from Bath to Melksham on the 272, then a single decker onward to Devizes. To some extend that has already been done - the 272 used to run from Bath to Easterton, but now the section furthest from Bath is the 270, sometimes but not always a vehicle change in Devizes for through passengers. But - people don't like changing bus too often, time is taken to change, and any delay to one incoming bus at the swap point leads to a delay to two ongoing services, or very annoyed passengers who have missed their connection.

So - splitting routes and switching vehicles have some application, but much (or most) of that has been done already for commercial reasons.

2. Can any bus go anywhere?

No ... some of the routes through residential areas require a smaller vehicle to get around all the parked cars that were not expected when the areas were built, or are areas that were built more recently without allowing for full sized buses.

No ... only buses that are up to "Euro 6" standards can run into Bath unless the operator of none-compliant vehicles is prepared to pay £100 per vehicle per day. Local fleets are mixed ... in one case, a bus route has been temporarily changed because its operator is awaiting delivery of smaller (village compatible) Euro 6 (Bath compatible) vehicles.

No ... low bridges and low hanging trees restrict double deckers

3. Do double decker buses double the fuel consumption?

No. They do consume more - but only around 25% more. Here's a diagram showing some typical figures. Where buses are running at reasonable load levels, the fuel consumption per seat is the figure to look at, so you take a bus seat 3 times the distance you take a taxi seat on the same fuel consumption.

But bear in mind that this comparison should be short term in detail as we move towards alternative (electric) vehicles. I would anticipate that a larger vehicle will still use more energy, but less energy per seat.

4. How sure can we be of what loading will be from day to day?

On a very frequent bus service, "we're full - wait for the next one" is reasonable, but on a service that only runs every half hour or less, it is not. Here in Wiltshire, we don't have the massive fluctuations based on weather that you'll find in seaside towns. And actually the bus operator can make pretty good educated guesses. But, still, they need a fleet of vehicle that copes with most peaks, and that will sometimes mean sending out a bigger vehicle than necessary.

I was ... amazed ... to hear of a double decker on last Saturday's Rail Replacement service from Westbury to Chippenham. It's in the photo at the head of this piece at Melksham Station. Typically, most train regulars avoid travelling on "trains replaced by buses" days, and furthermore we are still under some restrictions, people not moving around as they did a couple of years ago. However, from my personal observation, the bus was busy and under social distancing rules, the use of a double decker was necessary and correct. Top marks to whoever figured this out ahead of time!

5. Are double deck buses slower / less attractive?

From loading and unloading times, they can be - especially with modern health and safety which waits for everyone to be seated at each stop before they move off. Time issuing tickets / checking passes is also extended.

On 'thinner' routes, traffic may be significantly higher if 3 smaller vehicles (such as Optare Solos) run in an hour, rather that one double decker. It's a more attractive service, but it does mean up to 3 times the number of drivers, more bus bays needed at hubs and bus stations, and more road congestion.

Conclusion(s)

For the most part, the bus operators are being efficient, and the routine appearance of lightly loaded double decker buses on your street is worthy of asking about, but you can be re-assured it's not far off the best arrangement possible at the moment.

And, remember, that just at present England is slowly re-opening. Public transport use has been really depressed and that's what you may have observed. But already growing back in places; 9 got off and 6 on a lunchtime single decker on 272 (Bath to Devizes) I saw the other day - add in the through passengers, and it can't have been far short of social distanced capacity!