 If you think about what kind of things can happen, what we call as, but as we construct highways, what happens? Two things happen, rather the suburbs develop, so as travel time decreases, you would want to commute from further distances that means you prefer expanding the region within which the work circle is there, you start commuting from far, that is one, that is reactive after the capacity is there or based on travel time, you can travel further, but as soon as highway capacity itself is bigger, that region starts to develop, just imagine all the construction and township advertisement is for saying that highway is going to come here, airport is going to come here, metro is going to come here, just the mere news about highway capacity, capacity expansion itself has already result in development of the region and then your capacity follows, just that mere fact of addition or just the mere fact of announcement of road construction itself results in the size and region within your desired travel distance to go up, so we can bring that aspect also inside the system, let us just call it a simple variable called as size of region within desired travel time, this is size of region desired travel time becomes larger than overall population using the road network also increases. As travel time comes down, the size of region within the desired travel time is going to increase, as highway capacity becomes larger, the size of region that is going to be within the desired travel time is also going to increase or our own example within India where even just the announcement of this road network expansion can result in the size of region within desired travel to increase. In Panvel, airport is going to come or a bigger highway is coming, metro is coming, the price of land and building is already quadrupled in anticipation of all these things and by the time your road construction has finished, you are already under capacity. So, now a simple idea of ok, there is congestion, let us do the road expansion is not enough, we need to look at how ok when there is road construction is highway expansion, how are people affecting purchasing the vehicles, how many trips they are making, how can what else affects the attractiveness to driving as well as all these things now has to go together, it is not enough for government or policy maker as ourselves to only worry about just let us look at road construction, leave everything else to market economy, no you cannot, you need to if you want to control this travel time, then all other we need to look at other places also like for example, Singapore is considering as has done that you need to get a permit before you can add vehicles in the region. So, this is one loop which they are stifling by using policy, what is the average vehicles per person then they have introduced delays, you need to stay there, you need to apply and after sometime you get permission for doing that and that will effectively control vehicle in the region that controls the traffic volume, but then still people has to travel, for that people has to be happy. So, if people takes long time to travel either in public transport or otherwise travel does not need not be only in one transport, there will be always pressure to reduce the congestion, Delhi metro before metro how are people travelling, but now also there is huge traffic, how are they commuting before metro, that is because there is so many other dynamics that is happening into play other than simple road construction, as soon as it was there people started buying more vehicles, average trip let increase, trip per day increase which again results and comes back to travel time to satisfy whatever you are doing to similar levels as it was previously. And as I told you in desired travel time we need not be exogenous, we assumed exogenous initially, but then you would like to also bring it endogenous, to see where all we can have points of leverage to control it, like to make driving less attractive we can introduce more public transit is it possible, how will it get affected, so that is a also thing that we can try because many times when you are looking at cars and vehicles it looks so nice, but what we also need to do worry about is public transit and they are dependent on and they are also sharing the same space, it is not only for cars and private vehicles we also have public transit. Now, let us briefly look at this public transit aspect, so let us just go with revenue, so let us say public transit as a ridership falls revenue is going to fall, revenue is depends on your public transit people plus just for short I am going to write P T public transit fares, so I am going to have fare as well as I am going to have the revenue is nothing but fare is whatever ticket price, ticket price in number of people can result in revenue falling, yes correct, okay, oh sorry, yeah public ridership increases revenue increases, okay yeah sorry positive, but public transit also has costs to run the facility, okay, so now costs and revenue it is going to affect my profit, as revenue increases my profit increases, as cost increases my profit falls down, as higher the profit I may be able to calculate our view discounts or reduce the price of the fares, right or if revenue starts falling down then I end up increasing the fares or profit falls down or I go into loss then increase the fares, right, that become negative feedback or I do two things, if as profit falls down, so it is kind of counterintuitive but I told let us give direction positive but I want you to urge to think in terms of deficit, deficit, think in terms of deficit in sense because all public transport transits are running in loss, so it is easier to think in deficit, so as more the loss happens a public transit is already negative, they are not making any money it is in loss then they can either increase the fare, right, so let me just change the direction of that loop, let us just call it deficit and I am just going to change the direction of it, as revenue falls down deficit increases, I just made this thing and as deficit is more then I increase the fares, so that is to increase revenue but I do other thing also, I change my public transit network itself, I stop some buses, I have to cut costs, I have to lay off people, I have to stop buses, it may not go somewhere, right, so which after some delay public transit network itself as deficit is large the network falls down, as network falls down cost also falls down, right, our network is big then cost is big, I need more buses, I need more transport etcetera, so this is your cost cutting, this loop here is your cost cutting loop, this here is your fare revision loop, so I am going to revise my fare, as my network is big I am going to reduce my adequacy of public transit is big and this is a very interesting loop, so as my public transit network is good then adequacy is good, but other way let us take a look at this, ridership is falling, the revenue is falling, my deficit is increasing, so I am reducing the network, so adequacy of public transit is going down, then what does government do? After a delay after some time it invests in mass transit, your metro is coming, this is your let me just call it as mass transit loop, so adequacy falls down, then they do mass transit which increases the network size, thus network size increases it becomes adequacy, right, this is when the government decides on mass transit, the cost cutting loop and that I can do actually one more connection, it is public transit, fare also affects the driving, as fare is more driving comes down, I can complete the loop there, oh yeah fare affects your ridership, I am putting it indirectly through attractiveness driving or you can do it here, yeah that is why public transit fare increases, attractiveness driving falls down or fare comes down, attractiveness drive increases, fare increases, oh sorry, fare is higher, attractiveness driving is higher, sorry, fare is higher, so let me quickly come back here and wrap up, so yeah that is taking that, size of region we expect to go after the capacity is increased, but sometimes as the news of the capacity itself, people we discussed that it can increase the size of the region, like people invest in property just because highway is going to come 10 years later, that is what I meant, I think it is just illustrate that there is no strong connection, but there is some link between these variables, so we did all this actually, it is a nice, we did up to this loop based on the descriptions that we just gave, one way is to again go through this loop to figure out what is happening, each of these loops are nicely marked, stroke of relationship, mass change, expansion, fare increase, cost cutting and what happens when one increase and decrease, it gives a nice feel, there is one more link, from this to the next one, only new addition is this one, size of region within travel time as it increases, it reduces adequacy of public transit, people have already started occupying and what are we doing something in Domivili, but there is no bus facility there, there is no public transit there, but already that has expanded, so then that will force you to buy vehicles, so that as soon as new region comes and buses not even connected there, that means it has already become inadequate, so that is that you cannot get there on the bus loop, so we had gone through all these things, started as open loop view, then moved to a closed loop, then dynamics of traffic volume, then growth of sub road, mass transit, death spiral, so these kind of models age in better decision making, so it is not just a simple highway construction, now you need to not only invest in one humidity, invest in two, three things in parallel, let us do construction at the same time let us see how we can invest more funding to improve public ridership, the same time let us see how we can control the traffic volumes by providing better facilities, if every region is going to have a small economic area where you can buy your provisions and movies and all those things amusement parks, gardens etc., that can incentivize people to make smaller distance trips, so you need to invest in multiple activities, so these kind of narration helps in that level of planning.