[Music] foreign good morning everyone and welcome to the lesson that talks about the types and layouts of interchanges um this will give you a good idea on the different types of interchanges and how they are normally laid out so what we'll start with is we're going to start with what are The Interchange types okay and then what are the two types so the first is something we call a service interchange okay service interchange is an intention that taxes between a freeware controlled a high-speed Road and then another lower classroom now this lower class Road can either be a lower speed Road or a higher speed road but based on my experience is you find service interchanges normally are located between two expressways or two high speed high traffic roads while an access interchange is just like the name says it allows access for example in Texas is normally between two or more freeways and they're normally low speed and these are connecting to given aspects of a community there are mainly providing access as the name says access interchange and you find that access interchanges have normally in lower levels some is compared to a service interchange a service interchange has higher level of service because cars don't get to stop you find that most of the services interchanges for example let's talk about the roundabout before you come before you come to the roundabout you have to stop and then the cars can continue that you select by the roundabouts there's most likely a giveaway well uh a systems interchange uh the high there's a higher level of service so you can see the cars that are trying to make the different Maneuvers can continue moving at the different high speeds so when you're choosing the type of interchange to use make sure you have this in mind am I in an area where I need a service interchange let's say two motorways are meeting and then I have to cut off all the different uh movements now the difference in the service interchanges is based on how higher the level of service you want so if you want a higher level service use something like a semi-directional ramp if you want a much lower level service use a loop so that's how the interchanges are varying in regards to the configuration so I won't start with the first one so we have a dumbbell interchange dumbbell interchange looks like a dumbbell okay those things we use in the gym and you find that this interchanges comprises of two roundabouts so you find that normally two roundabouts on either side and it normally has one Bridge structure running and this is the advantage normally it has over the rotary roundabout and the challenge with this it's very difficult to modify in the future because the configuration is limited so you either find people either keep switching between a dumbbell to a diamond because they can make this signalized or in case you have issues where the signals fall you make these roundabouts then finally is you find that if you have to set up top Plaza store pluses have to be located on the ROMs so you can end up putting two plazas on the ramps on areas where uh people are joining the expressway for example here I'm on where Left Hand Drive so you would put a plaza here or a plaza there so this is the first one it's called the dumbbell now ai as you're seeing you're gonna find that most of the time um this is uh used as a service and access interchange okay and access integens mainly use provide access there are very few cases because cars have to stop so its level of service is a big lower so I find that this most cases will be an access road that's linking to communities and all so the next is the rotary stroke the roundabout interchange this is quite very popular and I think this is something you've seen around so The Interchange is like a dumbbell and this comprises of just one roundabout with ramps on either side so it's like a dumbbell but we just one round about rather than two roundabouts but you find that the difference between it and the dumbbell is you need two structures okay two breed structures it's very hard to modify in the future and as I highlight it's very good connection for terminal for arterial roads and is very compact so urban areas this is a very good interchange so if you're having urban areas where you need to connect people have this as The Interchange of choice top plazas again as a earlier highlighted they should be located on the ramps so then you have another one called the single Urban interchange single point Urban interchange normally called the spui Now The Interchange has a single point of contact which is at the center here so you find that there's only one signal and these different Maneuvers all the cars that are coming are using this one signal and it has one big structure which is very expensive so you find that this can go to roughly 15 to 18 million dollars just uh of how expensive it is compared to the others and it's easy to modify in the future so you can convert it to a diamond later on but it's very good for urban because it's very Compact and you find again the top plazas will be located on the ramps now this has one disadvantage in case in developing countries where uh we tend to have issues with our electricity if power goes off this interchange has one problem there's a lot of confusion here how do you handle the different aspects of The Interchange if there is no power and that's a very very big disadvantage with this interchange in developing countries but countries where you have very stable power this will be something to go for so if you're in a country where you find power goes off for one electricity is all for one or two three days be very careful when considering this interchange these are some of the challenges I faced when I propose these interchanges so you find that some areas are like no we think a single pointer bunny interchange has high level of efficiency because you have one signal and it's controlling everything pedestrian movements are working at four but if you have power challenges like in some of the areas in my country I wanted a single pointer of an interchange but you have to think about how you're going to handle the times when the power is off or it has a problem there is a lot of confusion the next is the diamond interchange so the diamond interchange is like close to a single point Urban interchange but now you have two signals on either side so there's do you have two points of contact okay and you have to signalize Junctions on either side uh with ramps so you have the signals here and then the signals here uh this is a title one but it's the concept is the same so this is wider so you can say in such a way the ramps have a higher level of service with the separation so you have much area to allow for the right Turners between the two signals or you can create a tight one where one signal is here another one is there circumcis when the signal is here the other one is there so it's quite really tight um but the concept is the same it's very good for urban as I mentioned and again you have to put the top classes on the edges so again you can modify this to a dumbbell in the future if you have issues with signals so if I like in South Africa they've had to convert most of this from to roundabouts because some of the time the signals are down I think two of them so we're going to the next type of interchange which is the diverging diamond interchange so the diverging diamond monitor change is the same as the earlier mentioned demo data change but it handles conflict points in quite a very intelligent way so rather than having these two arms continue parallel as earlier highlighted so you have this swerving that happens and then it swells the bit back the beauty with this is it allows traffic that's coming to interface with traffic in the same direction now remember if you're traffic in this other direction this was straight what would happen is you'd come here and interface with that traffic but you find that traffic that's moving the same direction interfaces traffic that's moving the same direction and then that switches back this is very safe and it's very good for traffic movement very good for pedestrian movement in terms of the configuration uh it's a much safer design than the earlier design then we have the trumpet interchange now the trumpet interchange is like a trumpet more details will be provided in the trumpet module and this interchange comprises of a directional ramp semi-directional ramp and then a complete loop I Define these are serving different levels of traffic so the semi-directional ramp is having a much higher level of traffic than a loop and it has one structure so one one of the hardest things it's very hard to modify in the future so if you want to maybe introduce a loop around here it's normally not well and it is something you consider and you maybe provide a wider Loop here and you need more land and then try to improve it in the future and the best thing about the trumpet is it's very good if you you are trying to terminate one Expressway into another so let's say this was one freeway and you're terminating into another a trumpet is normally the best option one has a high level of service too and not the highest but it's a very good as a terminating interchange and then two is it's it has one tall Plaza which allows connection for for like you need only one tall plus rather than having a number of top classes on the different amps and you'll find that this is normally used as an access interchange all as a service interchange so it can serve as a service interchange all an access all you have to do is you can improve the red eye you've used here to make it even having my child about service so then we have the Cloverleaf interchange this was very popular in the 1950s and this was revolutionary when it started so this interchange consists of four loops and four outer ramps so these are the loops that I just allowing traffic to maneuver from one freeway to another and again here it's the same thing and the outer Loops okay now as time went on and you find the third one structure so this was brilliant it just needed more line because then they had more land in the 50s and it was very easy it was so beautiful I mean everyone loved it the problem was one was uh there was a weaving issue here so you have traffic that's coming from the loop and traffic that's trying to come from uh Trend come from the interior so you'd have to end up having this connector distributor rods that would be running parallel and then disconnected distributor rods connect back and with time people started to run away from these conventions but if you have a rural area where you you you you two expressways are connected this is a very good uh very good starting point and the beauty is in the future it can be modified either to a partial Cloverleaf or turbine or a stack depending and it's a very good connection again this the top plus I should be located on the freeways rather than on any of the ramps here or something so the modification of this could be something could have a partial Cloverleaf so where you get rid of some of the loops and then you introduce the ramps connecting direct this is another form of interchange and uh this as Alia mentioned is suitable as the Cloverleaf it's suitable for a while you have a huge right of ways and in the future you can modify this to a turbine or a stack and the top classes as early highlighted are located on the ramps I mean on the freeway and some of the things to notice about this is the conveniency And in regards to the connection um you find that people don't have to move such a longer distance you can reduce the right of way needed rather than having one other extra large loop here I think they're the facility you end up having a partial Cloverleaf and and that's good so then you have a stack interchange this serves as a service interchange okay this connects of the numerous directional Loops so all what you're seeing here semi-directional ramps semi-directional semi-directional the moment you have a lot of these and they are stacked this is what we'll call a stack interchange now of course the number of Stack interchange you could have a diamond stack you could have in uh a Cloverleaf stock but the whole point is once you start having a lot of directional arms that are stacked upon each other it becomes a stack interchange okay it's very easy to modify in the future because you can end up having more stacks and again the top classes are normally on the ramps and the maintenance cost for this is rather High you find that the maintenance cost for the global leaves are much lower compared to this and that's one huge challenge then we have the turbine the turbine this consists again of numerous directional ramps it's not it's like the start but a bit what you're having is you have a much higher level of service so a stack is very good for an urban area and it's compact uh because you find that most of the times you could be even using radiuses of roughly 90 to 100 to 200 meters to to achieve this so find you just have directional arms that 200 150 meters constantly and there's a and it's in urban area so you find this land used is well utilized now a turbine is you have a higher level of service okay but you need a huge right-of-way so you find that you could start out with a Cloverleaf and then change into a turbine now the bit with the turbine is you can achieve radiuses of roughly 300 to maybe 900 and that means people can maintain a higher level of service by having a higher speed as the maneuver these different interchanges okay and it's also you can modify it in the future if uh if to a stack to something similar to reduce the right of way but the maintenance is really really high for this and the very good example is in Dubai and we'll be drawing something like this in the course I've also be drawing a stack in the course we'll also be drawing a Cloverleaf a trumpet a single point rotary and a dumbbell okay so check the different modules to check out and then we have something called the Y Interchange to be drawing this is in Switzerland what this consists of it's still a service interchange okay it consists of two directional ramps and two outer ramps and it's uh it has a higher level of service because of the directional ramps at a much higher speed so yeah maybe roughly 300D and 600 here so you can achieve speeds of roughly 70 kilometers per hour or high here and it's very good as a terminating connection so now this would be where you have a trumpet now someone could choose why don't I put a trumpet here and the reason is a trumpet has a much lower level of service than a y interchange so if you feel you need to have people having much higher speeds because the trumpet is going to limit the speeds to 50 to 60. why this you can have 60 to 90 depending on how you design it so you find that this is better it just has a much higher level of Maintenance in regards to the other thing I like about it it uses much okay almost the same land as the trumpet but I think it uses a bit slightly more it's a very good terminating connection for freeways so this is the Y interchange okay and there are many different modifications of this y interchange uh you could have it it's skewed a bit no but so I interchange so the number of more interchanges that we can speak about but I feel like if I go through these you have a very good understanding of the different types of interchanges