Go one, have another one. Who's counting?

How much would you spend on a new dress? Or for you girls out there, on a new car?
Now how much would you spend if you were only going to wear/drive it three times? What if you were only going to use it once?
Yes, of course if you were not going to derive much use out of it, you’re less likely to spend vast sums of money on it, correct?
So keeping that idea of frugal efficiency in the front of your mind, let’s look at drainage design. Yes, I know. I can hear you all saying, “But that’s the fourth article I’ve read this week on drainage...” But bear with me, I’m sure you’ll learn something new here:)

Let’s say you’re the mayor of an Israeli town, let’s call it Mazkeret-Yankele-on-the-Galilee, and the town is in need of a complete overhaul of its drainage system, which is simply lots of large, generally tubular pipes, underground, that carry away rainwater. And Israel, for most of the year is generally dry (and hot and sunny, which is wonderful). So what size should the pipes be? Yes, you think this should be a straight-forward question for the City Engineer, only I forgot to mention that in our scenario the City Engineer for Mazkeret-Yankele-on-the-Galilee happens to be your brother-in-law who, though a fully qualified engineer with a framed certificate in Latin, lorem ipsum, from one of the finest technical colleges of Swaziland hanging on his wall, just by chance missed that lecture on pipe sizes. So he’s passed the buck to you.

Clearly the bigger the pipe, the costlier it is. One short pipe alone could cost thousands of shekels, so if you decide on a 50cm diameter pipe, instead of a 40cm diameter pipe, then the cost of the entire project could jump by millions.

A problem, true? Which is why you’re not an engineer in real life. Or probably why you’re not mayor either.
How does the engineer go about it? Well he takes a look at precipitation tables. Or, in other words, rainfall figures. How much does it actually rain in Mazkeret-Yankele? you ask. (This is a brilliant question, well done, maybe you should run for mayor). And thanks to the sterling work of the Israel Meteorological Service and friends, we have such tables. Now what?
Well the engineer can design a network based on a size of pipe that will be capable of dealing with the rainfall that occurs in a typical year, and in some not-so-typical years too. But according to the tables, maybe once in every 25 years there will be a storm of such magnitude that the drains will not be able to cope. There’ll be flooding, mayhem and havoc. There’ll be flotsam and jetsam, and then’sam. There’ll be calls for resignations, and lawsuits, and homes wrecked. Which could all be avoided if the engineer chose a larger pipe. Only that would be more expensive.
This now becomes not an engineering issue but a political and municipal one. The size of pipe, and hence the total amount spent on a drainage system, boils down to a question of: How often is the town willing to put up with flooding - once every 25 years? or, if Mazkeret Yankele was awash with cash, once every 50 years?

Now I may be exaggerating but sometimes it appears as if the drainage systems of some Israeli cities work on the once-in-a-year principle. In other words, the council chose a size of pipe that is able to deal with all rainfall up to, but not including those heavy storms that occur... um... well every year, actually. Our drainage systems work superbly for most of the year (i.e. summer), but fail to cope when it rains. Last week, it rained in Tel Aviv and I literally had to wade across King George Street, which had become King George River.

The same principle can apply to roads too, but here Israeli town planners apparently lean to the other extreme. A town has to decide how wide each road should be: It should be wide enough to deal with the traffic that uses it, but there are busy times of day (rush hour) or year (Independence Day) when traffic is heavy, and other times (nighttime) when it’s dead quiet. So how many lanes should there be? One can see plenty of examples of three- and four-lane roads crossing the country, which for most of the day are empty. Here’s one in Tel Aviv (photo taken at 9am on a normal workday, January 2012):

Would it not be more sensible to design narrower roads with fewer lanes, freeing up more space for housing, parks, public areas? And improve the public transport system that would reduce the expected traffic flow during those peak hours of the day?

It’s not such a crazy idea. Have a look at the House of Commons in England. This is the chamber where 650 members of parliament meet, discuss, argue and pass legislation, but how many seats are there? About 408 (It’s difficult to be precise as there are no individual chairs, but rather long upholstered benches). When the chamber was originally built in 1860, and again when it was rebuilt after being bombed in the Second World War, the decision was made that it should be that size. Why? Because most of the time, the chamber is bare. Not many turn up for the debates. And when there is something special on, having elected representatives sitting in the aisles, or on each others’ laps, simply adds to the atmosphere:)

I predict (and my prediction is being given here free, for you, no purchase necessary) that at some time in the future, we will see road-narrowing in Israel.