Here's an overview of the game's setting and the entrepreneurial spirit that should be driving the players as they simultaneously encourage driving by their in-game customers:
Horseless Carriage is a game about the dawn of the automobile, a time when cars were invented, and no one quite knew yet what this new contraption would look like and what features would be essential. Early cars sometimes used levers or pedals to steer and a wheel to accelerate. Brakes were not always seen as essential, but sometimes an outside spot to take along an onboard mechanic was. This early, super innovative period occurs in the development of many new product categories. Players are cast as aspiring industrialists trying to find out what features the public will value when buying these new, expensive, and utterly unfamiliar horseless carriages.