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Module 1: Pedestrian Characteristics and Flow Models

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Pedestrian Level of Service Based on Flow Models

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So in this lecture, we'll introduce you to the concept of a pedestrian level of service or P L O S. And we will show how BLOS is developed for two different or two specific facilities. One is the sidewalk or the footpath and the other is the crossover. So when we say a pedestrian level of service, they have a. Uh, varied definitions, uh, different researchers have given different definitions. However, uh, if you look at the key words, which are highlighted in red, you can see that it effectively is an qualitative measure of pedestrian traffic flow. Along with environmental factors that might affect the perceived level of comfort, convenience, safety, security, and the economy of workers. Right. This is kind of the overarching theme. In a pedestrian level of service, qualitative measure of pedestrian traffic flow, along with environmental factors that might affect the perceived, perceived level of comfort. Right? So, uh, for, uh, for many centuries, uh, we have just provided, uh, for, uh, sidewalks or even for that matter the roads. Uh, and we have looked at it only from the point of view of. Uh, engineering or design perspective, we have, uh, only in the, um, uh, recent past decade or two decades or so in India, we have started to think about what is the user's perspective and how do we. But take into account the user's perspective while building these facilities. Because after all we are building, these are all public facilities, they are being built for the users. So how do we take them or their perception into account while we are building these facilities. And BLOS is one such measure that takes their, uh, perception into account similarly, uh, other, uh, there's uh, such as, as Alisha, they have also defined PLMs as a Measure for explaining current facilities, situations, and equipment of infrastructure in streets, and also evaluate the quality of service. So you would see that it is a, everybody kind of has the word, uh, quality or qualitative in their level of service definition. Uh, finally, the Indo has seen, which is the most recent document that has come out in India. Uh, it defines PLS as a measure for assessing the operating condition of a facility in a quantitative manner. It denotes the level of comfort provided by the facility to Pakistan. So now we are into, at CMS saying that they have developed that quantitative mechanism for developing PLRs, uh, in, so if we, uh, if we look at a broader picture yeah. The macro level, we, since we have seen the macro level, uh, macroscopic models, uh, you may remember the speed and flow model and it is a, it is a parabolic model. So. How these level of services are defined essentially is that this entire parabola is divided into different regimes. Okay. So if your value falls in any one of this accordingly, they are being defined as a, B, C, D E R F. So for example, if you have a flow on a facility, a flow of. 30, uh, people per minute per meter. And you have, uh, the speed of around say 1.3. So you would see that this would fall in the regime of somewhere in level of service C. So what this tells you is that. Well, uh, the facility that you have currently is holding, uh, is, is able to hold, uh, accommodate, uh, 30 pedestrians per minute per meter. And it's able to give you, uh, a maximum speed off or is able to give you a speed of one point average speed of 1.3 meter per second. So, whereas as, as opposed to that, there's a maximum speed possible off. Two meter per second, but because of this increased flow, now the speed has reduced to 1.3 meter per second. So then you start making, uh, thinking about, uh, should you improve the facility or should you, uh, make the facility wider? So how can you kind of go from a level of service C to a level of service B and maybe eventually to a level of service? However, whenever these trade-offs are made, there is always a component, a money component involved. Because, uh, to move from a level of service C to a, B may required that you, uh, widen the facility, widen the sidewalk, uh, by a meter. And the length of the sidewalk is maybe four, five kilometers. So you have to pour in that much of concrete or whatever material that you're using. So there's money involved in it. And do you really want to put in that much money, uh, for improving it from level of receipt to be, that is a judgment call for, uh, the local urban, uh, the urban local bodies. Which they often make, but here we'll stick to our, uh, technical, uh, point of view and, uh, understand how these levels of services yeah. Defined. Uh, this is another way of a very popular way of defining the level of service. This is defined on the base of two parameters, pedestrian space. And florid. So you would see that a pedestrian space of greater than 4.9 meter square per pedestrian. And also at the same time has a florid, which is less than or equal to 12 pedestrians per minute flow rate. So yeah, 12 penicillins per minute per meter. So what it shows is that you have a very, uh, comfortable space for the pedestrian, but you're rate is very low. Remember in the last lecture we discussed. That, uh, as the pedestrian space increases, that means within that 4.9 meters squared, there's not another person at all. So although this one person may be very comfortable walking, but this entire space is not being utilized. So the flow rate is very low and hence such facilities, our level of service, a so then it makes you think, do you want all of your, uh, sidewalks to have a level of service? Eh, We want such low flow rates and provide so much pedestrian space. That is a judgment call that needs to be taken many countries that have fewer or lesser population density. Uh, fewer people walking on the streets. Their sidewalks are most likely to have this kind of, uh, uh, level of service. But again, remember these thresholds should be set as per your, uh, local conditions, right? So you can say that if your local conditions are. Uh, are such that there is a high pedestrian volume and the, and the, and the, uh, and the population density is very high. Then maybe these thresholds can be lowered or, um, uh, can be made higher as per your local conditions. Right? These, but these are just guidelines. These are showing new guidelines as to how levels of service can be delineated between a, B, C, D E N F. Okay. So there are different threshold values that are given here. The level of service F is well, it's a very, uh, congested situation and the space is less than 0.6 meter square per person. So that is kind of gives you guidelines saying that if your facility has become so congested, that a person is having less than 0.6 squared meter for himself or herself to walk on. Then possibly it is time that, uh, you think about a better facility. And so you can then, uh, but which is your best facility, uh, would you accept a level of service D versus would you accept a level of service? C is something which is a judge, but called, made by, uh, many urban local bodies, because like I said, there's money involved. If you, you always want your facilities to be the best. But to achieve the best you have to put in money and money as you, uh, as you know, in today's, uh, environment is very less, very competitive. Uh, should the agency put in money in improving sidewalks or should it put it, put it in improving bicycle tracks or should it actually put it put in a user Putin for widening the road? So there are always trade offs that are made and hence a which level of service is agreeable is always a judgment call made by. Uh, the, uh, authorities in the urban local. So as part of the, uh, , uh, let us give you a quick run through of what are the different steps that needs to be taken in order to determine the level of service of the facility that you currently have. Um, maybe along the residential street, maybe along your residential streets or commercial streets. Oh, so and so forth. So what the first do is the first step of Axiom. It determines in which area you are trying to find the pedestrian level of service. So it determines identification of sidewalk based on land use. So whether are you trying to determine, uh, uh, the level of service in a residential area, in a commercial area? And terminal area and so on. So forth after you've determined that you then come to, uh, measuring the width of the sidewalk, which is a very, uh, uh, state forward way to do it, which is a little bit to the sidewalk. However, once you've measured the width of the sidewalk, the next step is to estimate the effective with now, this is something that we'll show you. How do you determine the effective? But essentially what it says is that maybe the sidewalk is four meters wide. But there are so many other things that are taking up the space in the sidewalk that effectively there is only two meters that the pedestrians can walk along. So that is essentially effective with, and then you observe what is the flow along that facility? Right. So how many people per minute are crossing a certain point along that, uh, facility? We'll give you the pedestrian flow. And, uh, subsequently once you know, the flow, you can calculate the peak flow rate, right? Low rate is nothing but pedestrian per minute per meter. So that is the flow rate. And based on the flow rate, you can then determine your pedestrian level of service. Okay. So these are, uh, it's the six step process in, in determining, um, what is the pedestrian level of service at your. Uh, facility alongside any of the land uses such as residential, commercial, et cetera. Okay. So, uh, in determining effective with, like I said, this is one of the basic steps in, uh, calculating the pedestrian level of service. So, uh, say this is a sidewalk, so this is a street, right. Then there is curb, and then you have the total width of the sidewalk here. The total width of the sidewalk here is given as, uh, let us see a 1.5 plus 2.5, uh, plus the effective width. So th these are all different components of the total width of the sidewalk. Now, there are two important things to be considered here. I, in order to determine the effective with other sidewalk, one is called the shy distance. Which is shown in this gray marks gray areas here. And one is the fixed object effective, but when is this fixed object? So fixed objects such as here is shown as a three, right? Fixed object effective. But, so what are these two things? Once you subtract the total width of the side of the sidewalk or footpath, once you subtract these two, the. Shay distance and the fixed object affective with, from the total width, you will get the effective with sidewalk. Okay. So now let us see, what is this shy distance and what is the fixed object effective? So the shy distance is nothing, but it's a buffer that the pedestrians give to themselves. To avoid accidentally stepping off the curb, brushing against the building face or getting too close to other pedestrians, standing under a awning or window shopping or something. Right. So what it is telling you is that if we go back to the slide, people who are walking on this sidewalk will never walk too close to the curb, right? Because they're always fear that they may. Follower rapport and actually walk along the street. And then there is a interaction with the vehicles and there is a probability of a crash or accident happening. So they always give themselves some distance away from the curb to walk. So in, in essence, what they are doing is they are not utilizing that space, although the space is empty, but they're not utilizing that space because that is a behavior in which we usually walk. So this 1.5 feet. Is what they have. Uh, people have measured on an average people leave from the curve and they do so also from the fence line or Lowell or the object line. So if you have a building phase of a building on this side, they will leave an additional 0.5 feet. So not only did they leave the 1.5 feet from this side, but when once a building phase comes, then they will leave another 0.5 feet. And walk effectively only in this white space. Okay. We have not gotten to that. Yeah. Not it got to the tree, but first understand what is that shy distance. Okay. So the shy distance is it with our space that is left by the pedestrians. It's the buffer that the pedestrians give to themselves, not only from the curl, but also from the building face. That is on that. So you don't want to walk too close to a wall of the building, right? You give some space. Yeah. So, so that is essentially what this shy distances now, secondly, uh, what are, uh, what is the fixed object effective with? It includes the objects, physical width, any functionally unusable space and the buffer given to the object by the pedestrians. These are three different things put together. Okay. So the objects, physical width, any functionally unusable space, as well as the buffer given to the object by the pedestrians. So for example, in this case, it's notice that there is a tree here. So what pedestrians would usually do is they would, in addition, uh, here, they were only taking a shy distance of 1.5 feet. So they were only. Uh, walking 1.5 feet away from the curb. But now here, because of this tree or this width of this tree or the diameter of the street, now they are giving an additional two and a half feet, uh, distance before this, uh, from the curb. So now it is 1.5 plus 2.5 around four feet of distance that leaving from the curb and walking here. So that essentially is what is called us fixed object effective with. So not only. Is the width to the tree, uh, affecting, uh, the movement of the people, but also the buffer from the tree. So they're also leaving an additional buffer here on the tree. Okay. So that is also affecting and in turn, what is also seen is that this affects for a very long distance along the sidewalk. So the tree may be right here, but essentially people do not do this kind of a movement. Right. People usually do this kind of a movement. Okay. So people don't come too close to the tree and then go past it. They start giving themselves a lot of buffer from way before the tree actually, uh, comes in their path and then go back to the original path we, after the tree has passed. So in essence, an obstruction causes takes up a lot of space. Which would otherwise have been used by the pedestrians for so some standard Shai distances that are given in the Indo at CMS, for example, if there is a bench. So the, uh, the shy distance is, uh, anywhere between 0.3, 2.5 meters. Whereas if it's a light pole, the shy distances. Anywhere closer to, up to one meter. So that is why many times, uh, it is, um, care is taken that the location of the light pole along the sidewalk is always a matter of concern, right? When you design a sidewalk along with the light pole, you're obviously bound to have light poles. The light poles are usually, uh, not put right in the middle of the footpath. It's put at least, uh, on one side of the footpath. Not obviously on the curb side, but on the other side of the building face site. Right. So that's why it has to be taken care of. The light poles are very necessary, but the way it is designed, because if you put it right in the center, it is effectively going to reduce the width of the sidewalk by almost as much as 1.1 meter. Okay. So that has to be taken into account. Again, then gives different level of service values for different types of land uses. Okay. So you have, uh, they have, uh, five different types of land uses and all the level of service values are, uh, given for different floorings, right? Flow is pedestrian per minute, but meter gives you the floor. It, so. If you have a flow rate in a commercial area, less than 13 pedestrians per minute per meter, then you are a level of service. Whereas if it goes anywhere close to up to 70, uh, pedestrians per minute, per meter, your facility or your sidewalk is completely, um, jam packed. So the level of service is not good. So you would see how it varies from. Commercial from a commercial area to a residential area. So in a residential area, uh, you would give, uh, at least less than 16, uh, pedestrians per minute would still be, um, a level of service. A whereas 16 for a commercial would fall in that level of service B category. So this can vary from different types of land uses. Okay. A more crowded as we moved with it F. Now if, uh, for example, uh, if you are given a situation where you have a 2.5 meter wide footpath around the transport terminal barricaded with guard rail on both sides, right? So you have to, uh, read the problem carefully. The existing peak flow rate is a hundred pedestrians per minute peak flooring. Okay. A hundred pedestrians per minute. What will be the level of service? Pedestrian level of service, considering pedestrians at the transport terminal areas use the Indo Axiom BLOS definition. So when, when we say use the index MPLS definition, we mean that use this chart. So based on this chart, because this chart is developed already now, based on your situation, what calculate, what is the pedestrian level of service? So let us follow those six steps that we have shown you in order to determine what the pedestrian level of service is. So remember in the first step you have to identify identification of sidewalk based on Landis'. So in this case, if we go back, what is the land use? The land use? Is it terminal land use? It's a transport terminal. So you are looking only at now this column, right? You're only looking at the scope. Second is measurement of sidewalk width. So you're already given that the sidewalk with this 2.5 meters. So it's a 2.5 meters sidewalk with in the terminal area. Next is the estimation of the effective with the facility. Now, how do you determine the effective with VA facility? Remember you have to, from the total width, you have to subtract all the shied distance as well as the, uh, fixed object, fixed subject. But now in order to help, help us this. Table has also been developed. So it is not necessary for you to go on the field and measure every object that is there and measure what is the distance that it is taking up or what is the area it is taking up? It has been given here that in case of guard rails now, because we said that this area is guarded by guard rails on both sides. So. We are to assume that there is nothing else, but God is, there are no trees. There are no, um, light poles, nothing else. It's only guarded by gardens. So in order to find out what is the shy distance to be used for gardens, uh, indication has given them is anywhere between 0.4, 2.6. So let us, uh, pick a value of 0.5 and sits in the gardens are along both sides of the. Uh, of the facility we multiplied by two. So if you subtracted from the, uh, total width of the sidewalk, now you have the effective with the sidewalk that you are dealing with is only 1.5 meters. Okay. So now you have already completed this step. The next step is to observe the pedestrian flow. Now the pedestrian flow has given us thousand pedestrians per 15 minutes. So how much will it be? Permanent? Let's do it by 15. So it's approximately 67 pedestrians per minute. The next step now, you know, the pedestrian flow, the next step would be to estimate the maximum or the peak flow rate. So the flow flow rate, because this is just the flow, just 66, uh, approximately 67, uh, persons per minute, in order to get the floor rate, you have to divide it by that. By the width of the sidewalk, right? So you can use 1.5 meter of width in the 1.5 meter of the effective with 66.6, 7% per minute are able to walk. So par meter, how much you are able to walk. So if it's 1.5 meters, uh, the floor is 66.67 per meter. It will be 44.4, four pedestrians per minute per meter. Now that, you know, the flow rate, you can use your table that has already been developed to determine the pedestrian level of service. So back to the terminal, back to the table, and we are looking at the terminal land use, and we have determined that the flow rate is a 44.4 pedestrians per minute per meter. So if you just go in this and find out where 44 lies, it lies right here. So the level of service of your. Pedestrian facility is level of service D so that is how you estimate, what is the level of service of your pedestrian facility using the indoor method? Okay. Now the second facility that we are going to, uh, tell you to, uh, uh, are tell you about, uh, when it comes to calculation of a person level of service. Is the crosswalks actor, signalized intersections. So you also want to measure how good the crosswalks are doing, right? Whether the crosswalk is allowing all the people to cross in a given, uh, with, uh, in a given time or with minimal delay and so on and so forth. So what this actually says is that this is defined by the highway capacity manual. Well, up in the U S in the year 2000, and it says that the measure of. Effectiveness of how well a signal or how well across walk is doing at a signalized intersection, depends upon the delay for waiting at the intersection. Right? How long is the person delayed while he or she's waiting at the intersection? Is the measure that helps you calculate the PLO is at a crosswalk, uh, at a signalized intersection crosswalk. So the delay. Or the average delay is given by this simple equation where C is the cycle length and G is D affective green time signal. So, uh, you America, the cycle length of a signal is nothing, but the time that it takes a signal to complete one full cycle of indications, right? So the minute, uh, the second, uh, that it turns green. You start your stopwatch and the entire four legs. So if it was a four legged intersection, so if it's a four legged intersection and the signal here turned green, all of these signals will have to, then this has to turn red. Then this has to turn green and this has to turn red. So all of this together, when it, again, this same signal turns green, that entire cycle is called the cycle length. Right? So from. The time elapsed between the green signal green indication in this leg to the next green indication, the same leg is called as the cycle length and the effective green time is nothing but the actual time available for vehicles to cross the intersection for the vehicles to cross the intersection. Okay. Remember, these are all cycle length is for, uh, green time for all the vehicles and effective green time is the actual time available for the vehicles to cross the intersection. So, what is the actual time? It's the sum of all the green times yellow time minus the last time sometimes the vehicles are the turn off. There's some time lost in starting up the vehicle, Samsung sometime lost in slowing down and stopping. So all of those times are two minus from the, uh, total green and yellow time. That gives you the effective green time. And then once you have those two numbers, you plug it in and you get a value for delay. So. This person who is waiting at the intersection to cross is delayed by some amount, some seconds per person, because of the cycle length and the effective green time at that signal. So if the delay is less than 10 seconds per person, then you would say that it is pretty good level of services. Whereas if the delay is greater than one minute per person, so every time a person comes. He, or she has to wait for more than a minute at that intersection to cross, or at that leg of the intersection to cross, then you would say that, uh, the level of services very poor. Yeah. And it also there's an indication or people have also seen that when the level of services F that is likelihood of noncompliance is very high. Meaning the person actually will not wait for the signal to turn. Uh, red before he crosses signal, meaning the signal for the vehicles, they will jaywalk and cross before the signal turns red. So the compliance or the likelihood of non-compliance also increases as the level of service worsens. So that's why we said that, uh, uh, when you are designing a signalized intersection, please also keep in mind the pedestrian volume at that intersection. Don't give only the green time for the vehicles to cross the intersection, but also reduce the delay or minimize the delay for all the people that are trying to cross that. Okay. Similarly, if we look at, uh, another problem here, uh, it says calculate the PLS of pedestrian crossings at both major and minor streets of a signalized intersection intersection, which has a cycle length of 80 seconds. And no pedestrian signals, right? So there are no pedestrians. The major street has a green time of 44 seconds and the crosswalk collect is 14 meters. Whereas the minor street, the crosswalk, like this 8.5 meters and has a green time of 28 seconds. It says to use the at cm 2000 PLS definition. So you had to use this table in order to calculate this delay. We know the formula, if you just plug it in. So for the major street, you'll see that the delay per person is 16.9 seconds. So which falls in that to get off B so far only the major street. So anybody trying to cross the major street of the four legged intersection. So if you have a. Uh, for like an intersection, maybe this is the major street and this is the minor street. Right? So anybody trying to cross this major street, he or she has to wait for an average of 16.9, nine seconds, which is categorized as a level of service B. Whereas if anybody's wanting to cross the minor street, this one, he or she only has to wait about 8.1 seconds. And that is a level of service. So, this is how quickly and easily you can calculate the level of service of people trying to cross at a signalized intersection.