Compromise is the name of the game
The advantage of having a large world to explore is that it creates an experience in which the player feels immersed in the world around them. We want a facsimile of reality, not the real thing. In real life it might take a day to walk 50 miles to the next town, but in our game it might only take 10 minutes. A system of risks and rewards should be established to govern traveling. Perhaps 10 minutes is still too long and this number might need to be adjusted, but walking is free and available to everyone. Maybe the longer you spend in an area and the more familiar you become with the region, the faster you can travel within it. The goal here is to make traveling to new areas a challenge in itself. Additional methods of transportation should be added to offer more variety and different risk/rewards. We could offer mounts like horses or pack mules that cost money to procure, but can travel further and faster than is possible on foot.
Simulating time with Ticks
Just came across a posting that sounded like a good idea:
Now I'm proposing the following: Take one day. That are 1440 Minutes. Or 144 TU (1 TU = 10 real life minutes). Now the player still has to spend TUs to do stuff in the game world, but he won't be able to improve the overall time. Now, the player has to plan his time more carefully.
I'm thinking about introducing sleep as well. Let's say a character that slept 4 hours (24 TU) has a training/battle efficency of 80%. 6 hours (36 TU) gives 100% efficency, 8 hours gives (48 TU) gives 120% efficency. What do I mean by efficency? It simply means how many turns you will have to use to do a task.
Let's say raising your strength to strength + 1 need 20 TU. With 80% efficency that means you will need (200-80)/100 * 20 = 24 TU for + 1 strength. With 120% efficency you'll only need (200-120)/100*20 = 16 TU. (this time increases as the attributes increase)Sleep will have to be done at the current turn, before you can do anything when the turn has been reset. So you'll login, be presented with a box saying: "How long did you sleep tonight?" and only then you'll be able to play on.
So we can apply this idea to traveling and allow the character to instantly move from one city to the next at the cost of their Time Units . Perhaps there will be other penalties to traveling such as being attacked by bandits or getting lost.
Calculating distance
Here is a simple application of the Pythagorean Theorem (http://www.mathopenref.com/coorddist.htm) to calculate the distance between two points. All we need are x and y coordinates for each of our locations. This information might be able to come from our map. Further investigation is needed, we need to have an established map before attempting any work on travel.
It might be nice to have a Travel button on our map that snaps from one city to the next with a rubberband. This would work similar to Google Maps and their re-route and waypoint feature. The map will have predetermined routes of travel (roads and waterways) that become highlighted as you mouseover them. Perhaps the player can unlock more routes as they gain experience to hidden or more dangerous locations.