Fimm made a post in the taxi topic pontificating about how much taxi use would you need to make before it is uneconomical vice a car.
I had my last car for about six years. Let's calculate whole of life costs
120 tax - £720
250 servicing (averaged, some very expensive years and some cheap) - £1500
60 MOT (I think) - £360
400 insurance - £2400
120 breakdown cover - £720
My purchase price depreciation was about £6000 and I paid about £800 (guess) in loan interest
I'm not going to consider parking cost at home or at work.
Total static costs: £12500 or £2083/year
Fuel cost was about 20p / mile
(n * 0.2 + 2083) / n
So 1000 miles is £2.28/mi or £2280 or £43/wk
2500 is £1.03/mile or £2575 or £49/wk
5000 is 61p/mile or £3050 or £58/wk
10000 is 40p/mile or £4038 or £77/wk
Even at 10,000 miles a year, every year (which I didn't do), over half the cost of ownership would have still been the standing costs. This was ultimately my biggest motivator in me selling up.
The taxi rate table is rather more complex in permutations, but let's assume cheapest entry (£2.10) and £2.17/mile thereafter and they never get stuck in traffic
2 rtn journeys a week at 5 miles (a trip to out of town shopping centre) would cost £25.9/wk or £1346/yr or £2.58/mile
4 rtn journeys a week at 3 miles (take kids to after school activities) would cost £34/wk or £1790/yr or £2.86/mile
10 rtn journeys a week at 2 miles (a commute from Ferry Rd to New Town) would cost £64.4/wk or £3348/yr or £3.21/mile
A car becomes economical compared to a taxi very quickly, if you consider many people will want to do all three of the above, plus occasional other trips.
I shall compare to public transport
A Lothian bus pass costs £600/yr or £11.5/wk
Two adult and two child passes are £1800/yr or £34/wk
This is pretty good by comparison. With careful home choice close, one can commute by bus and never need to drive.
And the cost of running a bike
A middle market bike has say a £500 purchase price, 5 year life before you n+1 it and £40 a year in upkeep. Sell for £80.
£124/yr or £2.38/wk. Even less if you DIY maintenance and keep it longer.
You have a family and want take them all places and make big trips to the supermarket and Screwfix?
An Urban Arrow costs £3300 according to their website, and let's say £120 a year in upkeep (servicing and leccy, maybe a new battery after 3 years? total guess). You're going to keep it til it dies (uh, estimate 6 years for the sake of this example)
£670/yr or £12/wk. It's a quarter of a price of a low use urban car over whole of life, and the majority of this is front loaded in the purchase price.
Methinks the bicycle wins!