Filton Abbey Wood - a great success? Emulate it just to the north??

[whole diary]

[grahame]

Got into a Facebook discussion on this ... where I'm assured that Patchway is closer to Aztec West than the end of the tunnel. My idea may be silly / impractical, but I'm darned sure it's not 2.63km from 1 (Station suggested site) to 6 (where the station entrance would pass people onto the Aztec West estate / nearest workplaces to the railway.

[Bmblbzzz]

I know someone who works in Aztec West and lives in Axbridge. Occasionally he cycles along the Strawberry Line and takes a train to either Patchway or Parkway, but he's found the trains too unreliable – not just late but cancelled altogether (at least when he tried this a few years ago) – so he usually drives or goes on his motorbike. Perhaps the trains are more reliable now but he'd need a lot of convincing.

I also used to work there but that was 20 years ago. I used to drive – from Horfield. I can't now imagine why on earth I would do this. However, I don't recall much trouble with parking or particularly with congestion, but I think that was partly down to the hours I worked (I can't remember what they were but I don't think they were 9-5).

If I were to start working there again tomorrow, and living not so far away from where I did then, would I take a train? Probably not, because I'd first have to get to Temple Meads, and TBH^▸ (to be honest) I might as well just ride my bike up to Aztec. Not something most people are going to do, though. Would it make any difference to my hypothetical commute if there were a new Aztec West station? No, unless there were also another new one at Ashley Hill or thereabouts; or if there were a through train from the Severn Beach line.

[grahame]

You highlight an issue that I hinted at in my discussion on Facebook that travelling to work by train involves not only a stations at /near work, but also a station near home, and a reliable service at the right times between them.   Bristol at present has one of the lowest proportions of its commuters travelling to work / college by train, as well as capacity issues  on the few routes it has.  Solutions include things underway already such as four tracks up Filton Bank and new(er) trains with more capacity and one hopes better reliability, leading on to other improvements such as are offered by MetroWest and suggested by other ideas from the likes of FOSBR^▸ (Friends of Suburban Bristol Railways).

A network with 10 stations offers 45 different journey opportunities ... with 20 stations, that rises to 435 opportunities. In almost any network there will be some journeys that very few people want, but with reliable, safe, affordable provision at the right time and frequency both ways, you'll find passengers making all sorts of journeys you hadn't expected and probably hadn't factored into your anticipated modelling.

[Red Squirrel]

You make some interesting points - your analyses are always interesting. Can we clarify something though:

Bristol at present has one of the lowest proportions of its commuters travelling to work / college by train...

When you say 'Bristol', do you mean the area covered by Bristol City Council? Or Greater Bristol? (or South East Wales, or whatever the dog-wagging tail of South Glos insists on calling it this week?)

When you say 'lowest', what are you comparing with? The core cities?

[Bmblbzzz]

A network with 10 stations offers 45 different journey opportunities ... with 20 stations, that rises to 435 opportunities.

I presume you're referring to Bristol network rather than general opportunities but could you explain the maths here, please? Preferably using nothing more complicated than arithmetic, if possible!

[grahame]

A network with 10 stations offers 45 different journey opportunities ... with 20 stations, that rises to 435 opportunities.

I presume you're referring to Bristol network rather than general opportunities but could you explain the maths here, please? Preferably using nothing more complicated than arithmetic, if possible!

With 1 stations on a system ... Just a pleasure ride
With 2 stations on a system ... 1 flow
With 3 stations on a system ... 1 + 2 = 3 flows
With 4 stations on a system ... 1 + 2 + 3 = 6 flows
With 5 stations on a system ... 1 + 2 + 3 + 4 = 10 flows
etc

Let's look at inner Bristol

Aztec West
and ...
Bristol Parkway
Patchway
Yate
Stapleton Road
Lawrence Hill
Temple Meads
Parson Street
Bedminster
Montpelier
Redland      =>  55 (11 stations on system)
--------------------------
and ... more general Bristol area
Clifton Down
Sea Mills
Shirehampton
Avonmouth
Nailsea
St Andrews Road
Severn Beach   =>  153 (18 stations on system)
--------------------------
and ... with some suggested new lines / services stations
Pilning
Coalpit Heath
Portway Parkway
St Annes
Horfield
Ashley Hill
Portishead
Pill
Ashton Gate
Hallen
Henfield
North Filton
Charlton
Long Ashton
Flax Bourton
Thornbury    =>  561 (34 stations on system)

Volume on flows likely to be very low where stations are close together, increase as distance increases, then decrease again as distance gets even longer.

[Bmblbzzz]

Aha! You're counting A to B and B to A as one flow. Now it makes sense!

[stuving]

Aha! You're counting A to B and B to A as one flow. Now it makes sense!

Maybe. But it's still not 435 is it? try 190. (You'd need 30 stations for 435 pairs.)

[John R]

1+...+n=n(n+1)/2, so yes if n=19 then the answer is 190.

[Bmblbzzz]

I thought it was n * (n-1). So if there are 20 stations, from each station you can go to 19 others. Multiply that for each station 19 * 20 = 380. Divide by 2 for flows gives 190.

[John R]

If you have 5 stations then you have 1+2+3+4 possible flows (=10)

Using the formula you have n=4, and 4x5/2=10.

You're really just expressing it in a different way, but doing the same calculation as you end up dividing by 2!

[grahame]

Aha! You're counting A to B and B to A as one flow. Now it makes sense!

Maybe. But it's still not 435 is it? try 190. (You'd need 30 stations for 435 pairs.)

Looks like I typed in "30" not "20" to my program - sorry about that!

[Bmblbzzz]

If you have 5 stations then you have 1+2+3+4 possible flows (=10)

Using the formula you have n=4, and 4x5/2=10.

You're really just expressing it in a different way, but doing the same calculation as you end up dividing by 2!

Yes.

Though it's not directly applicable anyway because, as Graham mentioned, it takes no account of where stations are relative to each other thus the likelihood of any individual journey.

[Western Pathfinder]

Hello and welcome to this weeks edition of Accounts Corner !.

[grahame]

Hello and welcome to this weeks edition of Accounts Corner !.

But there is so much to learn from a bit of arithmetic on published data