A Compendium of Interchanges....

[mightygoose]

well originally i started as motorway madness in the post your tutorial thread on ST [linkie]and now the new nam is out with highway onslope pieces... i thought it was time to revamp it and deal with interchanges as a subject.... this will sort of be an encyclopedia/mayor diary. as i meander through the vast possibilities of network interactions within the scope of sc4.


anyway here is a teaser showing the possibilities using the new highway onslopes grouped as close as possible in a number of situations i think will appear in alek's MD very shortly









more details soon

P.S. this seemed the most logical place for this thread.

[freedo50]

Wow that looks great, if only there was a place for me to use it! By the way, where did you get those embankment pieces/walls from?

Fred

[mightygoose]

update 1

i think i will begin with then new highway onslope pieces as they are something we are all new to. i might like to point out that for the first part until there is enough to make a decent compendium this will take on the form of a showcase. i will post construction tutorials if certain setups proove difficult for you guys to recreate. it will be quite advanced stuff here exploiting the nuances of the NAM to create quite complex junctions with sophisticated functions. to start of though some simple ones.



this is a raised HW. a hole has been made in the cutting and a roundabout placed in the gap. along one side of the raised HW is a OWR. on the other side is a terminating avenue on the diagonal. although neither connect to the HW(i told you i would start simple) this is a great space saving idea, as well as adding an element of realism.(you also get to use some cool junction textures).



this is the same from the other side.



this is a simple one direction on/offramp setup on an underpassing road. a slightly wider hole in the cutting is needed for this particular interchange.
it uses two perpendicular to road offramps that auto prompt when dragging the road under the elevated HW section.



again a reverse angle shot.

now this first updates most complex interchange.



this avenue underpass does not connect to the raised HW but has no direct right turn onto the OWR parallel to it. this problem is solved by a slip road onto the OWR prior to the traffic lights. however prior to the sliproad the OWR is in fact two way allowing for left turns from the avenue sliproad only.



here you can see the OWR crossing the avenue with a distinct abscence of a turning lane. in case this is a little confusing the last picture i have drawn the possible paths on over the top.



finally a couple of eyecandy shots.





thanks for stopping by... replies will be handled when there are more of them

MG

[Pat]

OMG OMG wow what wonderful detail here great job goose 

[thundercrack83]

This is a very interesting thread you've started here, mightygoose. These new On-Slope Highway Pieces are simply revolutionary. In the two posts you've done so far, I've already gotten a wealth of knowledge and inspiration! I can't wait to see what else you'll be tackling.

[freedo50]

Wow, you've started nice and simple, and yet by the end of just this first update I couldn't figure out your interchanges . Great work, hope to see some more beautiful and innovative interchanges.

Fred

[mightygoose]

update 2

well first replies....

thanks Patfirefghtr....

Thundercrack83, glad to be of assistance

Freedo50, as i said this will be quite an advanced tutorial, anyway the walls i use can be found here [linkie]

tbh i was hoping for more intellectual/technical replies but thankyou's are perfectly adequate 

anyway to business.



this is the bog standard NAM interchange for avenue crossing elevated HW.



unfortunately i have a problem with it. if this was a real interchange then each avenue median crossing would be used by two sets of traffic (red and blue). this would not happen in real life and thus a realistic approach is required.
my first attempt was a roundabout.



i also wanted the avenue to have uninterrupted through access. i did this with two slip roads off the avenue that plunge into tunnels to emerge on the other side of the roundabout.



only problem is plopping buddybuds underpass beta lots for OWR entrances reverses the direction as you can see on the avenue section with both pairs of arrows pointing south. you can reorientate the OWR post plop but that results in the model of the tunnel arpeture becoming obscured by the terrain texture. i came up with an interesting solution. although not perfect it looks the part and will still function the same.



basically i bulldozed the avenue underpass and replaced it with two OWR. then drag roads off at diagonals in the same place the OWR were dragged off the avenue. thus the junction texture looks reasonable at these intersections. use road instead of OWR for the slip roads and the road underpasses. as you can see it looks better as nothing is pointing the wrong way.

the thing with this junction is however it allows sims to turn around in their cars. now if your sadistic like me and dont want that to happen then i have just the thing.



after many headaches and much bulldozing i have managed to recreate a turbine interchange that is fully functional. i may tutorial this piece soon.



this i soon realised doesnt allow for right turns coming off the highway..... oh no... so with abit more squeezing...





anyway i think that the images speak for themselves....

todays eye candy



thanks
MG

[Glenni]

those interchanges are way cool! Must be real traffic hazards though:P

[mightygoose]

update 3

replies

glenni thanks, i think

anyway this is not the scheduled update as i received my first request.



El burro posted this unfinished interchange... i noticed a couple of things about it. its bigger than it needs to be, and there seems an awful lot of road, in fact there are not less than three ways of making a left turn eastbound to northbound.



in fact 5 if you use the purle piece of road to change from outer lane to main avenue, surely there is a simpler way.



i knocked up this. its smaller, and has less redundant road. however there are some subtle differences.

el burro's junction the outer lanes split. they can either use an express lane to turn left or rejoin the main carriageway and turn right or carry straight on. this loads the roundabout with excess traffic as left turns from the avenue have to still use the main roundabout for at least 3 tiles.

in mine however. the outside carriageways have no option to join the main carriageway and pull off to form the express lanes. in fact there is a feeder exit from the main carriageway onto the express lane. this alieviates congestion on the roundabout and also on the main avenue carriageway as those turning left would not rejoin the main carriageway in a system of similiar junctions.

in el burros solution in an even distribution of directional traffic, 5/6 of traffic from any one avenue must use the roundabout to continue their journey. in my interchange. it is 4/6.

in a quest to to minimise this further... if hes expecting 24,000 commuters and 16,000 are using the roundabout..... its only OWR remember.



this is El burro's second attempt.... and here is my analysis.



although hard to spot the black line depicts the roundabout in this interchange. first off this is not a junction between two 8 lane avenues, but i will overlook that point. secondly if you look at the red lines south to north. there are again three ways of going straight on. this however is less than five..... but arises mainly due to the lane swapping ability, note the green and blue lines south to north.

finally the pink and yellow lines depict the possible turns for each direction NS and EW. this time there are no express lanes for left hand turns. the large diagonal OWR are actually onramps for the roundabout as they are used for right and left turns. instead an uninterrupted through road is offered for the NS avenue carriageway. in this case the traffic using the roundabout NS is 4/6 but EW it is 6/6 being that the roundabout is formed directly from the carriageway of this road. these average to 5/6 of all traffic using the junction use the main roundabout.



well firstly here is El burro's second interchange recreated by me. its smaller, has less road routes, and functions identically to his. if you dont believe me you can check.



now by making both 8 lane avenues and giving both through rouads you improve the efficiency again taking the fraction to 4/6 again. however this interchange is bulkier than the previous incarnation you can see the logical progression.

anyway i hope that helps. in either case i have alieviate traffic by on the main roundabout by 4,000 commuters and compacted the interchange.

thanks
MG

[meldolion]

Oh my!!!
These are crazy Interchanges!!! Goood work!!

[El Burro]

lol, always ready to make a man look bad, bravo

I see what you've done an I'm very impressed with your take on it, I could no doubt demolish both of them and try what you've done because you've not used up any more space than I have.

By the way... this thread is incredible, you have some pretty insane interchanges

[mightygoose]

update 4

[/b]

replies...

Meldolion, thanks, im only trying to help.

well im not trying to make anyone look bad. you merely asked me to show you the flaws, so i did, El burro. im here to try and inspire peeps to use more realistic and varied interchanges in their cities. i dont put them in city environments to make it easy to see whats going on. thats your job.

Anyway considering todays surprise update upon request, today's official update will be a small one... tomorrow will be something abit special.

now for those of you who use custom sidewalk mod's, you will all know that the NAM 2x2 road roundabout will not conform.



as it has its own base texture, it ignores all normal sidewalks to display a maxis plaza texture. unfortunately its the most effective junction for the shape it occupies. but if your mean like most borough councils and need to restrict access and have greater traffic control what are you to do. with this roundabout they can go whatever way they like, disgraceful....



if the sidewalk texture really bugs you then im afraid that this is the only full access alternative. well this and the same thing rotated. unfortunately this isnt really that realistic, although im sure it can be found in places.



one method of restricting access especially in urban areas is to change one road to a OWR. but do it in such a way that another of the roads is restricted by joining the OWR instead of the other two roads. this can be demonstrated here by the road coming from the north. it is forced into a left turn by the OWR, whereas the south and west roads can interchange without impediment.



this has to be one of my favourite small interchanges. its so simple, to make it just draw the four roads into the square of the rondabout but dont connect any of the ends. then plop a single 2x2 avenue tile on top. as for the restrictions, the east and west roads can only turn onto the main carriageway forcing a left turn. the north and south carriageways can either turn left or carry straight on. this junction prevents all right turns. i have used this beauty in several places in my cities. as it looks good and is quite useful when used in conjunction with a OW network.

my second topic for today is a neat little trick that may be cool and look flash but is horrendously unrealistic.



on the left is an avenue corner with an inner corner T junction. not only would this be a traffic light nightmare, the road markings would be extremely complex, to ensure people didnt cut the corner. unfortunately these road markings are missing in the piece. on the right is a mor realistic alternative. it limits access to one avenue carraigeway so i would recommend an avenue roundabout in the vicinity to allow U-turns. this kind of interchange is normally found on straight dual carraigeways with limited access, putting it on a bend is not too far fetched. plus in my mind it looks better too.

finally a little head to head..... Marrast vs NAM in an underpass faceoff.



firstly NAM, lengthwise it is far shorter than marrast but it is two tiles wider. it has an open underpass using bridges for the roadway.



secondly Marrast, this is only 4 tiles wide and has a closed tunnel underpass. it is however a whopping 31 tiles long. but then again most inner urban underpasses on high capacity dual carraigeways(avenues) have quite long ramps.



tbh i dont think there is much of a winner. i think that the NAM underpass is better for rural areas where space is not an issue and marrast can pull it together in downtowns. although if you are planning on making a marrast underpass i would do it first. as some quite drastic terraforming is required to get the tunnel to dig.

anyway until tomorrow....

MG

[Fledder200]

Looks nice!! 
i love those parks!!

[Pat]

goose wow that is awsome what you can do and the interchanges talk about making my head pound trying to reallize the maddness LoL!!!!!

[Ennedi]

Hi mightygoose

I saw your thread. I have no time at the moment to prepare something interesting for you, but I will do it with pleasure.

I have an idea, wchich maybe can be interesting:
First, to formulate the problem. For example: Intersection of 3 avenues/RHW - T or Y shape, without collisions. Simple, gentle slopes, limited space in central area (exits can be long). Sorry for poor English.
Second, to show possible solutions.

I think it would be useful for many people.

[mightygoose]

update 5

right sorry about that..... i didnt want to put another 12 pictures on the first page.

thanks patfirefghtr for your kind words.
and also thanks fledder200.

to business. i promised something big and big i shall give.

M20 Junction 6





this beast is about 30minutes up the road from me and here for you to explore via aerial photographs....
[linkie]

it is special in the fact it is essentially a multi lane HW for over 1km. it has two OWR that straddle the main carriageway as feeder lanes for the three separate major junctions that form the designated junction 6.



coming from the northeast you come to what was the original junction 6. this is a standard overpass roundabout with a northern exit to an industrial estate, depicted by the streets and a southern exit to a nearby roundabout joining two major roads.



this is the south side of the western end to the interchange. the main road running north south is the A229. this is a connecting artery that runs from gillingham to maidstone. it also serves as a connector between the two major motorways in kent. the M20 and the M2. also coming off this roundabout is a main road running east to west also. you can see it bridging the main carriageway. and the other side runs parallel to the southbound A229.



this is the northern part of the wester end. notice the OWR pulling onto the A229 southbound offramp. this comes from a garden centre, the offramp for the garden centre is further north. i have shown you these two sections separately as they are in fact two separate junction types that merely overlap. if you dont believe me...



note the trumpet in red and the underpass roundabout in yellow. they overlap so each part's roundabout is overlapping the slip roads for the other.

i think it helps to show you some examples of use for this western end as it does look quite confusing.



heading eastbound making a right turn onto the A229 southbound. firstly you pass the original junction 6 and remain on the main carriageway before pulling onto the feeder road. you remain on the feeder road for 1km approx. then you bear left onto the offramp up to the northern roundabout. follow this round to the third exit. this road leads under the M20 parallel and adjacent to the A229. enter the next roundabout and take the second exit to put you on the carriageway.



heading westbound making a right turn onto the A229 northbound. firstly enter the feeder road just past the sweeping left hander of the main carraigeway. take the first exit and follow the corner round to the south roundabout. its a 35km/h limit on that corner. take the express lane onto the road adjacent to the northbound carraigeway of the A229. take the first exit at the northern roundabout.

i hope you enjoyed that little explanantion... i'll leave you with some close ups of this interchange.... enjoy...







thanks
MG

[callagrafx]

You do realise, of course, with every twist and turn you increase commute time?

[Colyn]

It is a good practice to restrict the number of images per post to 4 or 5 if you do stuff like this. Makes the page render faster.

[mightygoose]

callagfrx, yes but with speed boosts from the NAM realism can be acheived while maintaining useability. however this is a recreation not a design for practicality.... if thats all you have in mind why are your cities anything other than boring regular grids.

colyn. some city journals have as many as 30 photos in one update. i didn't think there were any rules ofr number of pics per post.

and both. thanks for the comments

[jeronij]

You are really taking the interchanges to its limits   ¡¡¡