Guesstimate 4 : Estimate the total length of roads in your city

Approach:

If we take Mumbai and say Blue Dart, it will take 1 delivery truck for a region like Andheri from the regional distribution centre.

Andheri is assumed as approximately 25km^2 in area.

A delivery truck driver would work for 7 hours a day driving, at a speed of 30–40 kmph (Andheri being congested).

So kilometers he clocks in a day: 30*7 = 210 km.

Now generally the delivery schedule is planned in a such a way that all deliveries happen in the most efficient way. (Operations Guys at the firm would be getting paid lakhs for ensuring this shit!, but then technology rules! )

So assuming up and down journey, I would assume length of the roadways in Andheri area as 210/2 = 105 km.

But provisioning for some scope of redundancy during the travel, I would take 70% uniqueness factor.
That gives us ~ 70km

Also some of the areas would be covered by bike delivery
guys: say 30% of what truck covers (as bikers cover short distances) = ~20km

Also 10–15 km for postman/walker delivery personnel : ~
10km

So total road length for Andheri ~ 100km
Now, Mumbai city area: 600km^2
So Andheri like region = 600km^2 / 25 = 24
Assuming a coverage ratio of the courier service to be 90%
Regions covered: ~22

So total road length ~ 22*100 = 2200km.

Keep Learning 🙂
The Data Monk