Sorry, but I have to strongly disagree with those horse riders. Maybe everything would be better in London (I highly doubt this btw), but it certainly would not be better in most of the US. The reason why, population density. The population density of the US is 31 people per square Kilometer (which I will denote as p/km). And the pop density of the middle and western states is much lower. Most countries in Europe are above 100 p/km, with the UK being at 246 p/km (source for all of these stats,
wikipedia "population density" ). Mass transit systems may be great in large cities like New York City, or Los Angeles, but for an area (city + surrounding area) that has less than a million people, and a low pop density, the transit systems just flat out suck. The city that I live in has an area population of about approx. 800,000 to 1,000,000 people and when I did ride the bus (only form of mass transit here) it would take me about an hour to an hour and a half to make what would have been a 15 to 20 minute drive. Until the pop density of the US rises to a substantially higher level, most of the US will sadly be driving cars.
Now for everyone using horses, this will probably never happen in the US for a few reasons. 1. Who is going to ride a horse to work when they can take a car that will get them there in probably 1/3 (rough estimate) of the time. 2. Now even though you do not have to pay for gas, you will still have to pay for grooming, feeding, horse shoes, etc. 3. This one is a bit more tricky. Are the horse riders suggesting that everyone ride their own horse? Or are they suggesting that a family would have a carriage or something? The problem with the first is comfort level. Who is going to want to ride a horse all day, granted people would get used to it, but those first few times could probably really hurt a persons back and/or bottom. The problem with the second is that the horse will obviously get tired much quicker. Also, the horse will probably go slower and the stability of the carriage could come into play, if you attempted to go at a fast/normal speed. 4. Finally, a horse is an animal. And animals are not always going to do what you want them to do. A car will keep going, as long as it has gas, oil, etc. A horse could get tired and just refuse to go.
I do not think these horse riders, or anyone, can really comprehend what it would be like if everyone rode horses. The stench outside of stores in the, I guess stables (parking lots), would be terrible. Also, who is going to clean up the horses "business?" The owner probably, but here in the US people litter, so I highly doubt they will pick up their horses droppings. Also storage, what are people going to carry backpacks or some kind of horse accessory to bring home the groceries?
I hate cars, I really do, but horses are a bad alternative in my opinion.