What road system works best? Driver on left side and driving on right side of road like in usa or the opposite like in other countries?
I’ve driven both systems often enough to be able to convert instantly between them, and as I live in the UK I learnt on RHD cars which use the left side of the road. Neither is better than the other. What makes far more difference is the driving culture and quality of roads, signage and junctions. The UK and Sweden enjoy the lowest rates of road deaths per capita in the world, and driving in both countries is a total contrast to driving in places with far higher death rates. India (drives on the left (like UK) is the worst I’ve ever been to. Within Europe, Italy (drives on the right) is by far the worst I’ve ever experienced. The US is generally OK but very variable: very poor standards in places like Chicago, Detroit (potholes everywhere!) and L.A. Pretty good throughout Florida except Miami. Much better across the border throughout Canada and vastly worse south of the border in Mexico. Considerate drivers make the biggest difference.
As long as everyone drives on the same side of the road, it doesn't really matter!
As long as everyone uses the same system it does not matter. However, the right side drive like the USA means you have to take your right hand off the wheel to shift the car, steering only with your left. Since most people are right handed, that to me does not seem to be the safest way to do it. With left side drive you keep your right hand on the wheel and do the shifting with your left hand.
Neither one has any advantages as far as traffic goes. Personally I think there would a slight advantage to driving on the right as the cars are set up to have for you to control shifting in a stick shift with the right hand which the dominant hand of most people. I think this is very minor though and something people would just get used to.
There is no best. It is a matter of the drivers following the laws on the road.
Some times there is no best way! Nations differ because of either social custom or because of ergonomics. In the US and places like it the standard goes back to wagons. The teamster kept the reins to the horse in the right hand because in most of us it is the predominate hand and more dexterous. Having more then one hitch of teams dictated the need for added dexterity. The left hand was used on the brake for descending grades. The brake lever was outboard on the left side. In England the custom is for the woman to be on the left, so that the males right arm is free to defend the lady. This is seen even in the US in marriage ceremonies and how couples are laid to rest (wonder why that connection?). Of course now the reasons are for the most part lost and to me it just doesn't matter. I just need to make sure I am on the correct side of the road for where I am driving.
As long as everyone does the same, it's all good.
One road system doesn't "work better" than the other. In countries (such as England) where the driver sits on the right but drives on the left, the road markings and traffic signs are all set up for right-side driving. In countries where the driver sits on the left (such as the U.S.) but drives on the right, the road markings and signs are set up for left-side driving.
Mostly just a handful of island countries like England, Australia, and Japan have driver on right side, but if you drive around Germany, France, Thailand, Ethiopia, Brazil, they are also driver on the left like the USA. It doesn't really matter as long as the driver and the stearing wheel are in the middle to best see the oncoming traffic.
The vast majority of countries drive on the right side of the road, only a handful drive on the left.