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Posted: 13 Nov 2006 19:24
by Dave
Well, unless it's the end of the motorway, motorways in Britain never connect with another road except by means of a junction - the likes of which we see in several pictures... And also see below. There are NO level crossings on motorways - nor dual carriageways (I don't think).

Thus - motorways are not interconnectable. This means we may need to specify "slip roads". I don't know what it is in other languages.

I'll describe below.

Excuse the bad drawings.

Posted: 13 Nov 2006 19:35
by Purno
Dave Worley wrote:Thus - motorways are not interconnectable. This means we may need to specify "slip roads". I don't know what it is in other languages.
Yeah, but motorways are interconnectable ( = connectable to each other, I assmume) via the usual big crossings (whatever they're called).

Posted: 13 Nov 2006 19:40
by Dave
Yes I was going there next :P

They're called interchanges and flyovers.

There are several designs of these tho, depending on the purpose the junction has.

Thus, I think it wise that we give people the option to build freely but select "slip road" as a buildable option.

Posted: 13 Nov 2006 20:04
by XeryusTC
Is a slip road a oneway road connecting one side of motorway A with one side on motorway B? Like the circles in the cloverloaf?

Posted: 13 Nov 2006 20:06
by m4rek
all the pink lines in the drawings are sliproads

Posted: 13 Nov 2006 20:11
by Dave
Sliproads also connect motorways with their junctions - which are usually above or below. Never on the same level though.

Posted: 13 Nov 2006 20:13
by m3henry
XeryusTC wrote:Is a slip road a oneway road connecting one side of motorway A with one side on motorway B? Like the circles in the cloverloaf?
yes

Posted: 13 Nov 2006 21:00
by Hyronymus
SimCity 4 calls them on-ramps, if that helps. But I think we can conclude that everyone agrees that motorways need a sophisticated way of crossing each other.

Posted: 13 Nov 2006 22:54
by Dave
Hyronymus wrote:SimCity 4 calls them on-ramps, if that helps. But I think we can conclude that everyone agrees that motorways need a sophisticated way of crossing each other.
That is the American term, yes.

Posted: 14 Nov 2006 07:13
by Purno
Dave Worley wrote:Thus, I think it wise that we give people the option to build freely but select "slip road" as a buildable option.
I'm not sure about that. I think I'd prefer the SimCity 3000* way, where a slip road is 1 piece of 1 pre-defined size (dependable on the type of crossing tho) which can be built.

Either that or have pre-designed flyovers and such.

Posted: 14 Nov 2006 11:21
by aarona
I would agree with making it SimCity-ish. Its a proven formula, simple to implement and does the job.

Posted: 14 Nov 2006 11:23
by Purno
It's simple for the player too. :wink:

Posted: 14 Nov 2006 17:50
by m4rek
i never actually figured out how to do sliproads in SimCity...

oh wait, i did, but that was just before i got bored of the game and stopped playing

Posted: 15 Nov 2006 21:58
by Dave
aarona wrote:I would agree with making it SimCity-ish. Its a proven formula, simple to implement and does the job.
Could you get a couple of screenshots for me?

I think if we're agreed, we can start discussing other roads.

For example - motorways in Britain are three lanes wide - But what about dual carriageways that are two?

Posted: 15 Nov 2006 22:50
by Hyronymus
Dual carriageways are double-deck motorways, right? I suggest we start simple. Also, note that motorways are 2-lanes per tile according the DD. I think that's silly.

Posted: 15 Nov 2006 22:55
by Dave
Hyronymus wrote:Dual carriageways are double-deck motorways, right? I suggest we start simple. Also, note that motorways are 2-lanes per tile according the DD. I think that's silly.
No - a carriageway is one lane of traffic.

A dual carriageway is two lanes of traffic in either direction.

In Britain a motorway is three.

Since I assume a road will = one tile, then a motorway could be three tiles wide?

(One way up road on left tile, two way road on middle tile with special graphical seperation, one way down road on right tile)

Posted: 16 Nov 2006 02:31
by aarona
Here is a picture from Sim City 4 (Rush Hour) which shows a "motorway", with a motorway junction and on and off ramps. (top right of the screen)

I'm glad the British have a sensible naming system. We have freeways which change from 2 lanes both-way, to 3, to 4 and 5 (with or without a dedicated bus lane). Some also have rail going down the middle between the two directions.

Posted: 16 Nov 2006 11:00
by Dave
aarona wrote:Here is a picture from Sim City 4 (Rush Hour) which shows a "motorway", with a motorway junction and on and off ramps. (top right of the screen)

I'm glad the British have a sensible naming system. We have freeways which change from 2 lanes both-way, to 3, to 4 and 5 (with or without a dedicated bus lane). Some also have rail going down the middle between the two directions.
Well I say three lanes loosely.

In the middle of complicated junctions, there'll often be a fourth lane to give drivers two lanes each for each direction. Then for a while there'll be two lanes, then it'll grow to three again.

There are *some* discrepancies but generally British motorways are three lanes.

Incidentally, in Britain we have the usual way of numbering motorways - M1, M4, M5, M6, M25, M40, M62 and so on and so forth.

But there is also a secondary category for roads that were originally A-roads (that is to say "primary" routes) that have been given motorway status.

These are usually referred to with an M in brackets. So the Aston Expressway in Birmingham (which leads to Spaghetti Junction on the M6) is the A38(M).

It's a little more confusing than I've made out.

Motorways - generally 3 lanes, occasionally 4 in busy sections.
A-Roads with Motorway status - generally 2 lanes, with 3 in some areas.
A-Roads - "Trunk roads" are often dual carriageways and are the main routes where motorways don't apply. A lot of A-Roads are single carriageway (that is one lane in either direction), especially in urban areas. I personally live on the A491.
B-Roads - Are almost always single carriageway and are like minor routes. The B4173 diverges from the A491 a little way down the road and carries traffic to the main road at the bottom a little closer to Stourbridge than the A491 does.
Unclassified roads are usually streets - and occasionally small countryside roads. In the cities, they will generally be a normal single carriageway but in the countryside they may be single track - that is only one car's width. Then there are passing places for cars to stop and let others through and so on.

As I said - a little more confusing than I made out, but to be honest - and I'm sounding my own country's horn a little here - I think it's a top-notch classification system that far outstrips that of the Continental countries.

Posted: 16 Nov 2006 11:45
by Purno
We don't need 2*3 lane roads if there's no ordinary traffic at them.

Posted: 16 Nov 2006 12:15
by Hyronymus
No, indeed, just 2 x 2 should do :).