I think this is ridiculous. The age limits imposed upon each license is done so on the basis of responsibility and skill allocated to the age group. The license categorization of normal, middle, and large vehicles are done based on size, and the danger risks imposed by a vehicle increases with weight. So it doesn't make sense to allow people to drive vehicles for which they haven't tested their skills out for large vehicles.
(In that sense, I feel it impractical that people can drive motorcycles once they receive a normal license - you won't even get to practice riding one at the driving schools! )
(image from: http://response.jp/article/2013/09/09/205954.html)
There's a rift between the rules and reality, and it certainly isn't about the categorization of vehicles by weight - it is in the age restriction. Since Japan has an established Driving School system, I believe there's no harm in lowering the overall age limit to, say, 15, with limitations such as the exclusion of students.
The good news is that the Tokyo Metropolitan Police Department is considering that option too.
This is so similar to the situation of "illegal" drinking that permeates the Japanese society - drinking of 18 - 20 years old, especially. 18 is the age that most people basically are considered "adults" now, finishing high school, which although isn't compulsory education is basically considered one now, and either become employed or move on to college. Either way, alcohol comes into one's life prominently around the age of 18, and it really doesn't make sense that society continues to avert its eyes from the fact, while there is silent agreement and acceptance upon that under-aged drinking.
Yuca mentioned in her presentation that there's this psychological system within us that the more one represses a (negative) thought, the more one thinks about it. There's also another study on the reason that children around preschool like saying "vulgar" words like "poop," with the reason being the instillation of the idea of taboo in them, and the excitement they feel by breaking the taboo of saying those words in public. (Can't remember where I read about it, sorry.)
Ignorance of disparity between reality and theory will do no one any good.






