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Module 1: Design Guidelines for Pedestrian and Cycling Facilities

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Intersection Sight Distance and Supporting Elements

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In this lecture part, we'll be looking at the design of cycling infrastructure and especially we'll be looking at intersection and approach design intersection, site distance, and other supporting elements that will help you design bicycle tracks or bicycle lanes in your, uh, urban areas. So, uh, as far as IRC 11 is concerned, what they have, uh, identified a methodology of, uh, uh, determining severity based on different types of intersections for bicycle, for bicycle users. So for example, if an arterial road is, uh, intersecting with an arterial road that has the highest possibility of. Uh, severity if a bicycle is involved in an accident. So when you're designing any bicycle lane, which is at an intersection of two arterials, one has to be very careful and the design has to be very safe. Similarly, however, the other Tim, if an access road is intersecting with an access road and because these two types of, uh, access roads have very low speed of regular. Uh, traffic. So the severity, even if a bicyclist gets into an accident or a crash, the severity levels is the least. So there is this type of a matrix that IRC recommends based on severity. I actually also recommends that traffic lights are, or traffic signals are not very. Are not the most safe way of, uh, negotiating a bicyclist through an intersection. Uh, they would rather, or one should rather design or design for roundabouts or great separate intersections in case of, um, uh, in case of bicyclists. So the best design would be roundabouts are the traffic circles. If they're smaller circles, if they're smaller roundabouts, they're called sometimes called traffic circles. So. Uh, in case of pedis, in case of bicyclists, uh, at an intersection, IFC recommends having a, um, roundabout rather than a traffic signal traffic signal is the, maybe the second best option as, uh, in, when it comes to safety. Right? Uh, great separated options are always the last options, uh, because essentially they are very expensive to build and maintain. And hence, although they may provide the best form of safety, but. We are always, that is always the last option to have, uh, to have to be constructed at an intersect. So, uh, again, there are different types of intersections, roundabouts, signalized, junctions, great separated, and on signalized intersections, which have traffic coming associated with it. Right. This is the type of intersection which we often, um, uh, we often see or observe in our urban areas where. Two lanes, uh, two roads intersect, but there are, there is neither a roundabout. There is neither a traffic signal. It's a signalized intersection. So when two on signal, when two lanes intersect and there is no signal or no roundabout at the junction, or it is an uncontrolled intersection, then it has to be traffic calmed. So there has to be some traffic calming measures that needs to be taken. So drew, so as so as the, so that the bicyclist can. Uh, safely negotiate the intersection. Uh, so similarly, this is what this table shows you the different types of, uh, again, uh, different types of intersections between different types of, uh, route categories. And what is the most likely. Um, uh, uh, what is the most likely form of traffic control that should be in place in, uh, in order for the bicyclists to safely negotiate that intersection? So if it is two arterials that are intersecting around abouts at both at all, the three or four arms should be provided, right? Even if it's a T junction, which has only three arms, you can still design a roundabout for. For that kind of injunction. And obviously if it is a forearm junction, you can have a roundabout. The next option should be signalized. And the next option, the option after that should be great, separated for motor vehicles. And the final option is great separation for them. It lists now these, uh, grid separation for the cyclists are already, uh, a very recent phenomenon that is being adopted by some of the, uh, uh, developed nations, uh, in Europe. Uh, in Europe, especially in the Netherlands, you would see some, uh, major intersections that sees a lot of bicycle traffic. Uh, they have a great separated, um, great separated arms at the intersections, which are meant to be used by bicyclists. Now, uh, we'd not see any such intersection in India yet, but if the, uh, Gaze requires a certain intersection are such a need for an intersection. There's all, there's always an option that IRC has provided this. Similarly, you can read through the different types of other, uh, options that are available to you, especially when different types of intersections are different types of roads intersecting with each other, but always remember give reference to a roundabout. As opposed to a signal. And if there is, uh, uh, if too low volume roads are intersecting, then there has to be traffic calming measures, uh, provided, especially if they are on signalized. Right. If there aren't signalized, there has to be traffic calming, such as, uh, some rumble strips or a narrowing of the road at the intersection on Soren's At a signalized junction. So IRC now gets into the details of different types of, uh, junctions. So at signalized junctions, the cyclist will incur significant delay, uh, just as the motorcycle, just as the motor vehicles incur delay that there will be significant delay if in case of a signalized intersection. So in order to avoid that kind of a delay for bicyclists, there are different types of. Uh, there are different types of techniques or designs that can be, uh, provided at the junction, for example, that can be segregation at or near the intersection. So once all the traffic approaches the intersection, that could be a separate bicycle box, uh, which is ahead of the, um, traffic, which is ahead of the, uh, traffic, which has stopped here behind the stop line. Then there is all the pedestrian crossing. And I heard of that. There could be a bicycle box, right? This, this kind of blue box, which allows all the bicycles to come past the traffic and stop at the signal, uh, ahead of all the traffic so that when the signal turns green, they are the first vehicles that can move ahead. So in that manner, the delay for the bicyclist can be reduced. Also direct connections between the cycle tracks and the box should be provided. So if there is a cycle track that is leading up, for example, if there is a cycle track, uh, here that is leading up to the box, which is, uh, here. So the cycle tracks should have a direct connection to the box, right? That will, uh, ensure that all the cyclists that are using the secretary do not have to mingle with, uh, the traffic, uh, in the. Motorized lens and can directly go into the box and wait for the signal to turn green. Sometimes provision of left turning traffic, uh, can also, uh, help the bicyclists, but mostly, so that's kind of left turning, uh, segregated, left turning lanes are usually avoided. And we'll see what, uh, IRC also talks about these kinds of left turning traffic. They may be. Uh, your left or, uh, left only lanes, or they may be through an left turn lanes as well. So if the bicyclists, if there are no, uh, cycle tracks along this, uh, route, and the bicyclists are sharing this kind of, uh, um, uh, right of way with the motorized vehicles in that case, uh, left turn lanes are left only lanes. Uh, sometimes are allowed, but it is often, uh, recommended that, uh, segregated left-hand lanes should be, uh, ignored because, uh, what happens is if you have happened to have a segregated left turn lane, uh, and you have a continuous free left, uh, going a free left for regular traffic, then the pedestrians, or even the bicyclists that are trying to cross. This road will always be at conflict with the left turning vehicles. So usually segregated, left turning lanes are not, uh, something that is recommended, but in certain low volume cases, you can allow, uh, uh, segregated left turns because if the vehicular volume is less and the cycle volume is high, then, uh, in order to reduce the delay for the cyclists, what. Prior to turn left, you can allow segregated, left turn lanes. Uh, also, uh, speed table can be used as a calming device. We've already talked about speed tables when we have looked at pedestrian crossings. So there are nothing better, uh, raised, uh, uh, these two, uh, uh, platform that allows, uh, cycles and pedestrians to, uh, cross the intersection. So that kind of, uh, rate crossing always. Helps in calming the traffic calming the motorized vehicle traffic. It reduces their speed, but they're always, uh, definitely second best because, uh, as we said, signalized junctions are the second best solutions. The best solutions are roundabout

Uh, this is why usually, uh, we, uh, avoid free LifterLMS. Because, uh, it, the studies have shown that there are no significant benefits to waiting motorists. Uh, and, uh, at the same time it causes a lot of friction between them, uh, merging motorists and the crossing of the pedestrians and bicyclists. Uh, though it does reduce the crossing distances in very large intersections, but there are more, uh, cons than pros. And hence we usually try to avoid. Free left turn lanes, uh, even for bicyclists. Uh, the next thing to, uh, design for, uh, is to, uh, is to take into consideration what is called the intersection sight distance, especially when the intersection is non-signal is unsynchronized right. So what usually happens is if a bicyclist, for example, Is here, uh, and, uh, he's approaching he or she's approaching, uh, signalized intersection. And if his line of sight is blocked by a bunch of trees, he's here. For example, it may be anything. It may be, uh, it may be parked vehicles. It may be, uh, it may be a building, uh, anything that, uh, obstructs his or her line of vision of, uh, and he, or she is unable to see this approaching vehicle, which is also moving towards. Uh, the intersection, then what might happen is, uh, this cyclist may or may not be able to safely negotiate through this intersection, right. Especially because this is on signalized, he or she may not be able to brake apply brake, uh, in time or, uh, maintain speed so that they are safely able to negotiate that intersection and so on and so forth. So usually what, what is, uh, seen is that there should be a sufficient. Sight radius that should be provided site radius of site distance that should be provided in order for this non-motorized form of transport to safely negotiate, uh, any traffic that is coming from the, uh, opposing direction, uh, or from the perpendicular direction. Right. Uh, so what usually happens is say at instance, a certain time period, a the vehicle, uh, the cyclist is here. And because of these trees, he or she is not able to see this, but at a next instance, maybe, uh, five seconds later, uh, the Mo uh, the, uh, bicyclist has now moved up to this position and the vehicle has also moved up to this position. And now this is the first time that he or she is able to see this vehicle, but he, or she only has about 10 meters left. Whereas here, if there was no obstruction, he had. Uh, the bicyclist would have had almost 55 times the distance and that would have allowed him or her to safely negotiate. Whereas now he has only one fifth, the distance, and this may cause some kind of a crash situation between the vehicle motor vehicles and the bicyclists. So this kind of site distance intersection sight distance is very, very, uh, important, uh, especially in case of on signalized intersections for. Uh, bicyclists. Uh, if you take another example of an unsynchronized, uh, and a signalized intersection. So in case of a signalized intersection, since the stopping the, since the stops, uh, stop bar is very close to the intersection at that point in time. And the vehicle become under, uh, uh, bicyclist would be. Uh, stationary. So at four, a signalized intersection, he or she would not require much offer stopping sight distance. Because, uh, he's already here. She's already stopped at the stop bar, which is very close to the intersection. Now his line of sight is pretty clear to all of the vehicles. So the distance, a, the stopping sight distance, a, uh, shorter stopping sight distance is also permissible. Whereas when he, when somebody is approaching an uncivilized intersection, it is always advisable to have a larger stopping sight distance so that he or she can. See this motorized vehicle and take a decision whether to break or to go through the intersection. uh, so, uh, in order to calculate what that distance should be or what this, uh, distance DEA should be, we can simply, uh, use, uh, the principle of similar triangles. Uh, so if, for example, considered the first larger triangle, when the cyclists is at this position and the car is at. This position. So if you consider the larger triangle of ABC, and if you consider the smaller triangle of a D E right, so a D E is the strangle, whereas a, B, C is the right. So this is the, if this obstruction, so that this is the time at which this bicyclist has first been able to locate this. Uh, motor vehicle list because now the motor vehicles has just crossed this obstruction point and as the ease or the edge is at the edge, right? So if you consider the similar triangles principle, then we can BC, uh, BC by AB, BC by AB is equal to E D by 80, right? EDB E. Now BC is, uh, BC is the distance. Uh, that this vehicle would have to travel in order to meet the bicyclists at this point. Right? So that is, uh, DB and AB would be the distance that the bicyclist would have to travel in order to meet the vehicle at this point. So that is da, uh, E D E D. We already know is the distance between the point where. At the corner point of the obstruction and the linear distance between the corner point under a straight line of sight of the bicyclists. That is a, and, uh, a D a D is I think, but, uh, the entire distance, da minus B B is this distance that'd be, is the distance of the edge of the obstruction to the straight line of sight of the car. Right. So if you know all these, each of these distances, you would be able to predict what they should be, or you will be able to measure what they should be. And that much off site distance has to be provided. And any obstruction that is, uh, in between, uh, the line of sight, uh, should be removed. So, if you look at a quick, uh, numerical, uh, a tall building is located 25 meters from the straight line of sight of the car at point C and 50 meters from the straight line of sight of the bicyclist at point E. Right? So there is a tall building. So this obstruction is it tall building? Great. That is, uh, located 25 meters. Uh, from here. So that's B is equal to 25 meters and 50 meter from the straight line of sight of the bicyclist. This is the line of sight of the straight line of side of the bicyclist. And it is located 50 meters or so easy to determine the values of a B and the site distance available to a bicyclist located, uh, at position, eh, Uh, if the guard is, uh, if the car, uh, the car is at sea and is approaching him on signalized intersection, which is 60 meters of it. So this is 60 meters. Okay. So if you have to know what is the minimum that should be provided, you can, again, simply use this. Uh, uh, similar triangles principle, you already know, uh, DB to be equal to 60 meters. Da you have to calculate a is 50 meters, which is given N uh, da minus B, but B is 25 meters it's already given. So you can calculate that at least 150 meters before, uh, approaching, uh, Uh, the, uh, line of sight, the state line of sight of the vehicle, the cyclist has to be at least one 50 meters away so that he or she can see that vehicle that is moving it, uh, whatever is the safe speed, uh, at, uh, that, uh, that, uh, intersection. So any obstruction that this allows, this type of distance should be taken away should be. Cut order intersection should be so designed that at least one 50 meters off site distance is provided to them. No, the next thing, uh, the next item that, uh, IRC, uh, looks at is the pavement surfaces, uh, on which such bicycle lanes or bicycle tracks are provided, uh, the, they are similar to pavement surface materials for pedestrians as well. So, uh, we have already looked at what type of materials should be. Uh, provided for, uh, um, uh, for a pedestrian crossing. So these are, these types of surfaces are similar, uh, for bicyclists as well. Uh, what has been noticed is that if there are, uh, if there are, uh, uh, bicycle tracks that are provided, usually, uh, there are parallel and perpendicular cracks that develop, um, and each of these cracks are very minor, but, uh, they do develop 13 in cracks and there are some projections. Predictions are nothing but abrupt rises in the surface of the travel way, uh, such as these, uh, that, uh, the result due to, uh, maybe crude patching or drainage grids that have, uh, sunk. So such kind of projections and cracks do, uh, make the surface uneven. And it does not provide a good comfort level to the bicyclists, uh, for, uh, um, bicycling on these surfaces. So, uh, such type of, uh, uh, Uh, preventive maintenance has to be taken care of so that other surfaces smoke. Uh, if you look at the different types of, uh, uh, pavement, uh, pavement surfaces that can be provided, uh, five different qualities are usually compared for each of these, uh, different types of surfaces that can be provided for bicycle tracks. Uh, the five qualities include, include right, quality or evenness. Skid resistance, ease of maintenance and repair the capital cost involved as well as the cost of maintenance and repair. So from the point of view of all of these five, uh, they are usually dated on a three point scale. Our IRC, uh, has developed a methodology of rating them at a three point scale. And you would see, uh, asphalt in case of asphalt surfaces. Most of them are, most of the qualities are either met or either desirable or. Uh, or a scale of two out of three, right? So as four seems to be the most referred, um, psych, uh, surface for bicyclists, uh, even, uh, concrete that's the capital cost involved is a highly undesirable because, you know, concrete, uh, costs much more than, um, uh, flexible pavements, uh, paver blocks have, uh, some ride quality issues associated with it. And ease of maintenance is not very. Good as well as meat, uh, repair, uh, maintenance is not very, uh, uh, uh, uh, not pretty easy with paver blocks and similarly for, uh, quartzite and granite. Uh, there are other, other types of difficulties that makes them undesirable. So most likely you will, uh, encounter, uh, bicycle tracks that are, uh, asphalt. And some of them could be concrete as well if, especially. If we can take care of the capital costs, uh, next, uh, IRC recommends certain traffic coming measures, uh, in order for, uh, the cyclist to feel comfortable while they're riding, uh, either in their cycle tracks or, uh, along with motorized vehicles as well. Uh, these are especially, uh, especially important if, uh, for example, a cycle track is, uh, meeting, uh, A motorized, uh, uh, motorized carriage way at an intersection. So there have to be, uh, such kind of, uh, traffic calming measures for the motorized people for the motorized vehicles. So that bicyclists feel very safe. So usually you would see a rumble strips, which are getting very popular nowadays and speed humps that are, uh, not. Uh, that the design of which is mostly in the, now in the form of a trap recital hump, rather than the good old, uh, speed humps that had it, uh, uh, circular radius, right. Perhaps recital humps, uh, uh, provide a platform on top. So you have, uh, you have ramps from both sides, and then there's a flat, a flat, a flat top, which allows, uh, the bicyclists to safely negotiate. These. Uh, uh, speed humps are rumble strips rather than the very, uh, high or steep, uh, speed humps that we usually see on the older roads or the older designs, right? Uh, three basic elements, uh, infrastructure road, user, and vehicles have to be considered when you're looking at, uh, traffic coming measures. At the variation in speeds between vehicles is the major cause of the accident, right? Because these motorized vehicles are going at a higher speed and the bicycle is set a lower speed. This variation in these two speeds causes a lot of crashes between, uh, bicycle system, motorized users, um, such a speed humps and rumble strips are always, uh, uh, they improve the behavior of more, uh, motorized vehicles as well. So unless you put these measures. Uh, in place, uh, you know, psychologically, the motorists always believes that, uh, the Arbonne road or the any street is for motorized vehicles only. So unless, and until you have such measures in place, uh, such kind of behavior would not change. Lastly, there are a lot of signs that IRC, uh, has, uh, uh, recommended, uh, firstly, uh, different types of. Uh, regulatory signs have to be in place so that they can be enforced. Uh, you might have seen no parking signs along the bicycle lanes. If there are dedicated bicycle lanes, there may be no parking, especially of motorized vehicles or any other bicyclists. Also parking on, uh, on the bicycle lanes sometimes, uh, is also not witnessed. So those kinds of signs. Have to be put in place. And then of course they have to be enforced also. But the first step is to put these signs up, uh, up and make people aware of these facilities. Uh, some, uh, uh, some highways do not allow bicycles also. So bicyclists also have to be aware of which facilities are for them and which are not for them. And they should not. For example, bicycle and expressways are grids or, uh, uh, great separated highways. Oh, that is not for them. Uh, then you have a compulsory cycle tracks for cycles only. You could also have a shared, uh, shared use paths, which are both for cyclists and pedestrians. Uh, they may be segregated, right? One side of the track, maybe for bicycles and, uh, for pedestrians and the other, maybe for bicycles. And also there may be some certain lanes where bicycle share the lane width. Uh, buses. So there are different types of signs, which are very essential for the users to understand and be aware of them so that, uh, uh, enforcement becomes, uh, easy and transparent. Uh, next category of signs are the warning signs, right? Um, you have to give way, uh, to, uh, bicyclists and pedestrians, especially when, uh, such kind of, uh, separated tracks are parts are. Crossing the motorized, uh, motorized tracks in that case, you have to, the motor vehicle has to give way to them. Uh, there are certain, uh, uh, cases where bicyclist ride along with the motorists are on the same right of way. So the motorcycle motorists have to be made aware that this lane is being shared both by non-motorized bicyclists, as well as by motorized vehicles so that they behave in that manner. Uh, maybe if there is a, uh, uh, upcoming cycle crossing, a warning sign has to be, uh, put in place prior to that, uh, the next, uh, set of signs, that information informative, uh, signage that provides information, uh, to, uh, the bicyclists as well as the motorists. About what are the upcoming facilities, uh, uh, parking facilities for bicycles, uh, for bicyclists, uh, maybe, uh, given, uh, information may be given about where you can park, uh, information about where the bicycle track begins. Right? If it is common for both bicyclists and pedestrians, such kind of tracks, uh, ramps where, uh, which are, uh, accessible for, um, uh, accessible to a wheelchair, a wheelchair users. As that kind of signage is also very important and also especially able, um, differently able to environment also, buddy, as in chill, the last type of inflammatory science includes, uh, whereas, uh, uh, public toilets, uh, for, uh, especially able people parking for specially able people. Remember whenever we are designing for an MTV, we have to take into consideration. Others are differently abled and especially abled people. Uh, so as to provide a universal, a universal design, right? So it's not only in the case of pedestrians, but also in the case of bicyclists, we have to provide those sites and the Republic telephone signs as well. Uh, these are just, uh, some applications of, uh, of these kinds of signage. So when, uh, when a cycle track begins, uh, when a cycle track begins, uh, at this point you have to have a sign, which says, Cycle track from here and have a private tree sign saying no motor vehicles in those tracks. Uh, when a cycle track is crossing, uh, a, um, uh, a, uh, motor vehicle, a motor vehicle lane, you have to give this kind of sign saying that, uh, the motor vehicles have to give way to the pedestrians and bicyclists. Uh, if, uh, if, if there's a shared cycle track, you have to have this kind of sign and also parking. For bicyclist has to be noted, uh, and proper signs have to be provided, uh, just the last, uh, uh, slide on, uh, some information about bicycle parking. Uh, parking in general, as we know is an issue in, uh, uh, in many of our Indian cities, uh, parking of vehicles is an issue parking to, uh, to be less is an issue. And so is parking of bicycles, an issue we have hardly paid any attention to. Uh, proper plant bicycle parking in many of the areas. Uh, mostly it is unorganized parking like this, but thanks to some of the newer technologies that have, uh, come up in the recent, uh, recent past, such as public bicycle sharing systems, uh, these have dedicated parking facilities, uh, for the bicyclists, uh, that you can rent, uh, proper bicycle parking facilities. Always help, uh, bicyclists to take up, uh, bicycling provides for last mile connectivity. Uh, it encourages people to, uh, use an empty modes and discourage them from, uh, using, uh, uh, motorized transport, uh, motorized modes of transport. However, uh, several design elements have to be taken into consideration while you are. Uh, providing bicycle parking, such as shade may be needed, especially for Indian con conditions. There should be some, some form of security that should be provided so that, uh, a bicycle is not for example, stolen, uh, control, uh, should be, uh, enforced properly. And at least, uh, the area that is provided should be 20 or 30% more. Uh, for optimum user, the future as well. So, uh, thinking about the future, thinking about attracting more bicyclists to your, uh, to your, uh, transit or to your. A hotel or restaurant use. So you should always provide for bicycle parking. So when you, when the next time you go to a mall and you would bicycle up to a mall, uh, please make sure to see where the bicycle parking is. And if there is no bicycle parking, please make sure to make a note of it and pass it onto the authorities saying that such public places, large public places should have a proper bicycle parking, right transit stations, places of importance should have proper. Bicycle park.