Why would one build a railway in the middle of a motorway? It's cheaper!
Why would you avoid grade-separating railways, either through tunnelling ground or having them elevated? In short: cost (acquiring land and compensating owners, etc)
Where the Elizabeth Line's construction costs surpassed $25 billion tunnelling through central London, there is only lane widening to consider for motorways (unless already had a convenient median).
A little while ago in Canada Montreal's newest metro on the block: REM automated light rail system along the freeway.
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| I increased my budget with my own animated GIF |
It's not uncommon in America too, usually in cases the freeway came after the railway.
Or see Roosevelt Boulevard, it already a median built into it in preparation for a subway that is 20-years in bickering over finances.
If it's not obvious, America had the most railway track in any country in the 19th-20th centuries, well, I didn't try as it's not the main topic but alas, some things confined to the past.
So you have Chicago, Los Angeles, Philadelphia but to name a few that have this... quirk of the transport world.
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In Berlin the autobahn (highway in English) was built 50 years after the Ringbahn (S-bahn/U-bahn trains that form a ring in the city).
Osaka in Japan also has some section of this description, albeit 4-lane for cars rather than the monstrosities you see in America.
Perth also has a 10-lane freeway with a bus lane on the outsides, and a railway in the middle. They're gonna extend the line, costing only $441 million AUD projected as of writing.
The consensus is highway median railways like these are bad, after all in those stations on the motorway - you're blasted with the sound of tyre friction that surpass 90 dB (think of being in a concert level of loudness), whilst every waking second feels longer than it actually is, as your perception is slightly warped by how uncomfortable it is to be there, even with some level of sound proofing.
Then, catchment.
Where are you placing stations to appeal to people that won't drive their car? A decent amount of catchment area is taken by the motorway itself. Therefore the areas the stations are in should be a destination despite these shortcomings, to be considered usable.
So I had a thought, is this doable with our M25?
Highway median railways, what could possibly go wrong!
Let's investigate,
- reducing it to two lanes and placing rail tracks
or
- widen M25 an extra road lane per direction, adding rail tracks in-between
For reference in my previous rail-related post, I did draw about an orbital Overground line at the bottom of my post about South London and trains (I didn't think of this on my own, ideas spurred by other bus enthusiasts discussion), which would vaguely parallel inside the M25 going to major centres.
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| Freeze frame Spot the train, I'll give you all the time |
Spring Garden being one of the worst designed stations, it's in Philadelphia.
Where do we start, we were meant to have four orbital motorways;
The inner-most scrapped - too many buildings would be demolished.
The second ring had parts of it constructed (most of A406) but mostly undone.
The third ring parts of it constructed, rushedly turned into M25.
The outer ring is the majority of the M25 as we have today.
Obviously the M25 being the single motorway that does the job of more than 2 intended motorways, it's been a hotbed of a mess.
Lane widenings in key areas have only gone so far. If it was even possible to instantly widen all the lanes, you'd end up with a positive feedback loop experienced in many American freeways (see that 18 lane LA monstrosity - traffic still bad)
Therefore, it is imperative there is public transport, namely trains, that also orbit London. We have the London Overground that does a great job of orbiting inner London. We need that replicated in outer London and perhaps even the border of London in order to reduce strain on networks, mainly reducing traffic.
Ideally you'd have completely grade-separation for this job, most likely requiring either mass-tunnelling (very expensive very quickly) or acquiring a lot of land, which is possible - can that satiate the many buildings that would be bulldozed as well as farm plots reduced... who knows, I'm merely typing a fantasy that isn't completely stupid albeit almost unreasonable by British standards.
On the assumption using the M25 is a lesser evil, then:
Costs:
For starters, new stations you're looking upwards of a £1 million, as much as £10 million. The likes of Reading Green Park which opened recently costing £6-8 million.
There's a segment below about stations and I've come up with 20 in my reasonable opinion, so up to £200 million on stations alone.
Car parking garages cost about £25 thousand, we'd roughly want that for every station with less-than-adequate public transport.
Twenty stations again add this cost to £500,000.
Rolling stock (including new depot) would cost a fair bit, Elizabeth Line with 70 trains estimated cost £1 billion.
New bus stations - West Croydon cost £4.5 million, even if it is a rebuild. Up to 15 stations are doable with bus connections, Heathrow is ruled out (already has bus stations to connect to), some locations not ideal for bus stations for the stations I've made (Brentwood parkway).
Costs up to £67,500,000
Extra buses to schedules
(£200,000 to operate each roughly, 252 294 370 might require +1, 234 require +3).
TfL costs amount to under £1,000,000.
No non-TfL costs; on themselves fortunately and unfortunately.
Not widening the M25 (i.e reducing road lanes) would definitely be cheaper and definitely be more disruptive short-term, perhaps even still moderately disrupted medium-term if there isn't adequate destinations transferred from the car to this railway.
Again, rail costs (Excluding land acquisition) between £12-20 million per mile. So £2,340 million,
Widening the M25 would cost a fair bit per mile, one of last motorway widening was... the very M25 itself! For a short distance, £272 million (£16.2 million per mile) in 2002 figures. £28m/mile in 2023 money.
M1 widening projected to be £21 million per mile in 2007. That's £33m/mile in 2023 money.
Using those numbers to do the same to the whole 117 mile long motorway would cost £7,722 million. Several billion of course.
Granted, it won't work like that in reality(Excluding land acquisition), so it may be more expensive, no amount of optimism allows for it to be as cheap as 2002 (accounting for inflation).
Again, rail costs (Excluding land acquisition) between £12-20 million per mile. So £2,340 million.
Rudimentary maths total: £10,331,000,000.
That's before land acquisition, contracts, construction delays, pushing costs higher.
Difficulties from an armchair perspective
Widening the tunnel under Waltham Cross could be impossible, let alone prohibitively costly.
Crossing the Thames (east side), given there is a tunnel and bridge on M25.
Heathrow area.
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| I forgot to add "Parkway" to differentiate most stations not connected to namesake areas |
Projected demand:
Put simply, over 200,000 daily vehicles use the M25 (over 8,333 an hour). 15% of UK motorway traffic. Let's put that to scale quickly.
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| Cars; 4 kilometres of road space 1 train; 200m of space Only 6 Class 345s an hour needed to meet the hourly estimated use of M25 |
So roughly, assuming at least half of them are car traffic, of which most only have the driver in them, then you'd get a quick maths like the above but worse.
Yikes.
Stations:
Dartford parkway
Swanley parkway
Dunton Green parkway (for Sevenoaks)
Godstone parkway (443 extended there)
Merstham parkway (for Redhill, and services to Gatwick. Buses terminating at Redhill extended here)
Leatherhead parkway
Byfleet parkway (for Byfleet and West Byfleet)
Chertsey parkway
Heathrow Terminal 5 (important)
Heathrow Terminal 2 & 3 (important)
Gerrards Cross parkway
Rickmansworth parkway
Kings Langley parkway
London Colney parkway
Potters Bar parkway (234 extended there)
Waltham Cross parkway
Epping parkway
Noak Hill parkway (252 294 646 extended to terminate there)
Brentwood parkway (connect with Elizabeth Line, new station)
Lakeside parkway (for Lakeside shopping centre and West Thurrock. 370 + non-TfL buses extended)
There were some sparse locations where, in hindsight would seem wasteful, though in reality no guarantee traffic wouldn't generate more than I anticipate if this came to reality. After all, many stations in the northern outreaches of the tube were desolate fields when extended, at a time before the Green Belt was established post-war, putting a dead end to many projects, notably for us Londoners - the Northern Heights Plan that would've seen Bushey Heath on the tube map, and Edgware connected to Mill Hill by Northern Line.
Timetable
It takes about 2 hours to do a loop of the M25, look up on YouTube.
National speed limit on cars is 70mph.
We want speed, so trains can do 100mph. We have plenty of those. Cutting costs to light-rail sacrifices speed, necessary for long distances between stops - unlike short stops between DLR or Tramlink.
Referencing the Joondalup Line again, trains have a maximum speed of 80mph where freeways tend to be 68mph or less.
By nature of the M25 serving Heathrow traffic and being down the line from Gatwick at it's southern tip as well as serving many centres, the routes chosen should be really well thought out and with data. Some things I do lack as I am just an armchair enthusiast.
Journey time around 100-120 minutes is my ballpark figure, not much below doing the M25 in a car yourself.
Segregated vs Interconnected
The pro with segregated is minimal delays from being interconnected, the likes of our Sub-surface lines and other similar lines globally do face the same issue. One problem somewhere on the line impacts all the lines to some degree.
The con is the very limited connections one can do.
Conversely, the pro with being interconnected is the many destinations one could achieve. The cross-London service from [almost]Oxford to Brighton can make a comeback using this M25 rail. Others could also be created.
In addition, other local lines could be added/diverted to use the tracks. Even in cases of diversions this will doubly be handy.
Ashford via Dartford to Heathrow
Brighton via Gatwick to Oxford
Southend - Potters Bar - Luton
Guildford to Stansted
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| An older idea of mine but using outer London mostly |
What do you think? Not as bad as my Acrossrail photo below maybe? Outrageous idea perhaps? All I'm saying is, if car-centric America continues this practice whilst the Germans/Japanese mostly had the practice happen afterward, then we can replicate the technique, preferably with quality like the Australians did.
Sources/watch these videos too!
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