How to profit on vehicles

Solution 1:

For the most part, road vehicles behave much like trains, except that you've got a lot more of them running around. There are some differences, though:

• Avoid turns and hills to the greatest extent possible. Unlike trains, road vehicles are always slowed down by hills and turns. Note that detouring to avoid a hill is usually a bad idea, because the multiple turns involved each cause a slowdown.
• Don't overload roads. On a clear road, running vehicles can pass a broken-down one; on one packed with oncoming traffic, they'll back up behind it.
• Make sure you have the right number of vehicles on the route. If your vehicles are waiting to load, you're losing money; if cargo is piling up at the station, you're losing station rating.
• Don't compete against trains for cargo. The station rating system used to decide who gets an industry's production favors faster vehicles, and all but the slowest trains are faster than road vehicles.
• Avoid overly short routes. It takes several days for a vehicle to get in or out of a depot -- travel time that doesn't add to the delivery distance -- so you need actual travel to make up for it.

• Accept that your road vehicles are going to have a lower profit margin than your trains. Trains move faster, which translates to higher payments, and can carry more cargo for their operating cost. Road vehicles are best for small cargo volumes or spread-out sources (eg. passengers and mail).

• Don't imitate the AI. I don't know which one you're using, but some of them have marginal strategies, while others have highly efficient ones that require insane amounts of micromanagement.