If everyone obeys the traffic laws, everyone saves time, every process in the country is more efficient, everyone is wealthier and safer.
There are a ton of second order effects:
+ Considerably fewer accidents, meaning more efficient use of medical staff.
+ Considerably cheaper insurance (all things being equal)
And tons of 3rd order effects:
+ A completely chaotic transportation system means it's probably difficult to transport a lot of things efficiently - and certain industrial systems may not be possible.
+ If people don't generally obey traffic rules, there are probably a ton of situations wherein driving would be literally too dangerous. The example is Germany: where they are very well socialized and follow the rules (even in auto making and quality) they can drive a zillion miles an hour on the highway, still relatively safely. You can't do that unless everyone plays the game.
'Intelligent Social Organization' is literally the foundation of civilization.
It's not 'natural resources' that make us rich, it's our institutions, intergenerational intelligence and 'rules' of various kinds: social, legal, cultural upon which the former two artifacts depend.
The irony of the parable is that the 'traffic cheater' may be doing something he 'needs to do' but it's that very activity which is limiting he and his own community's ability to be successful.