From: Leeuwarden, Netherlands
Yes, but a little addition to the above; roads or railroads as they are the same, are the key to a succesful supply system. Therefore you want to build engineer units, 30-40 engineer in each unit (they get EP's per turn per engineer, so 20 engineers earn 20 times... 3 or 4 Engineer Points per turn) In order to build something you need EP's for the Engineer unit, Raw (that's the ore stuff, see it as building material) and PP's Political Points.
So without railroads your units will be out of supply very soon, you will want to have them linked to your Supreme HQ. So that way your SHQ can provide its subordinate HQ's with fresh troops ... via Strategic Transport that your SHQ can do *if* it has trains available. Makes sense huh? Send troops via a railway system to the front. You can even use Trucks for Strategic Transport... but that uses Oil. And certainly in the early stages of a game you're short on everything. Because you want to build a railroad system, *and* you want to build shiny stuff like tanks/armoured cars/Artiller/Mortars but they all use up Raw and there's only one way to get Raw and that's to expand your Empire. Note the numbers on the top of your gamescreen. Green = good, Yellow = the amount you use up this turn, Red = bad meaning you are "producing" stuff but there's no Raw to produce it which means it's lost. Say you have zero Ore/Raw and you have set a city to procuding four Artillery... then that is lost, wasted, gone, better set that slider for Artillery to zero and max out the slider for say stuff that don't need Ore like PP's, Supply, Infantery.
Also note that in the previous patch, not in the latest haven't tried that one out, there are more cities producing things. Now it's handy to set quite a few cities under the command of the SHQ (check the colour of the left bar on a city = same colour bar as the SHQ) , because it needs the most supplies as almost all your army is subordinate to that SHQ they will also draw supply from it. But you can also attach some cities to local HQ's, so they get supplies and troops as well. PP's go always to the pool. So for PP's it doesn't matter to which HQ they go it's all added up. By attaching local cities to local HQ's you also prevent that the SHQ has to provide all of it's subordinate HQ's with fresh troops.
Building railroads costs ore too (select engineers, press R on keyboard, click on the hex you want a RR) ... so it can happen that you have say 600 ore available (most left number in the Ore tab), next to it is a yellow number which is the ore you're using up by the cities building stuff/guns/tanks/mortars, and to the right in the Ore tab is the Ore amount you receive per turn (depending on how many Ore mines you have and what lvl they are). Say that you use up 400 Ore for producing stuff. That leaves 200 Ore for building RR's, Forts, Airfield. Now by building RR's you see the 600 decreasing with every thing you build, do not *ever* get that in red, because that means the things you are producing in the cities are lost, not produced because the don't get enough Ore. The sliders won't change but it never gets produced. So either you have to stop your engineers from building more things *this* turn, *or* you have to reset some of your sliders to a lower number of Guns/Tanks/Mortars, or even things that don't need Ore like PP's Supply or Inf/ horses.
Oh and about horses.. they rule. Cheap, don't cost nothing, don't use up oil, etc. Armoured Halftracks are nice to have but only later on in the game.
The end. LOL