Some share of society believe that it is better to obtain one single legal system all over the world, while others think that each country should have their own law. I believe that the best option is to keep individual laws in countries.
On the one hand, if every country had the same laws, life would be easier for citizens. The majority would not receive fines for things they were unfamiliar with. In addition, it could in the future lead to the unification of the world, first through the creation of a single law, then language, and so on.
On the other hand, it would be inconvenient for a significant amount of countries. For instance, in the UK, where traffic rules are absolutely different. Moreover, at least few generations will need to get used to the left-handed driving tradition, which is the minimum of what will be new for them. Another massive issue could be with the redaction of laws, as each member must find a middle ground between everyone else regarding the new changes. At the same time, the government should allocate extra payments for those who will lead the parliament.
In conclusion, I think that it is better to save the system that we have at this moment and not to spend time on the reconstruction processes.