I can't seem to build roads.

[Delyn Locksmiths]

How many engineers do i need in a unit to build roads?

[Barthheart]

It's not the number of engineers exactly. It's the number of engineering points, EP, that a unit has. Each turn all the eng subformations in a unit get so many EP, I forget how many. It costs EP to build roads, different terrain has different costs. I believe that plains cost 10 or 20 EP. If you have about 20 eng in a unit you should be able to build a few raod sections every turn. Less at it will take a while for the EP to build up.

Generally I build eng only units with 40 eng and 2 trucks. They can build lots of things in a few turns.

[seille]

1 engineer generates 2 EP per turn.
And a engineer unit can store up to 5x the EP turn production.
 
40 engineers make 80 EP per turn (fully supplied) and that unit can hold max 400 EP.
Like Bartheart said 40 engineers are a minimum for fast road building. I prefer 60-80 (plus trucks)
to be fast even in bad terrain. And it helps to cross rivers.

[Veldor]

I vote for 60 as thats enough to build an airfield/port in one turn as well. Fits in 3 trucks and enough that you can also afford to loose a couple and still complete all tasks..

[seille]

Yes, usually 60 are enough. My 80 engineers are usually for VERY bad terrain with many rivers
or for the case i need a fortification EVERY turn. For example in russia 1941.

[dsvitak]

Thanks for this forum!

I had 120 engineers, through woods, and I thought I would be able to build more than one road section per turn.

This thread explains PERFECTLY how to use them.

[seille]

120 engineers are nice in case you have 6 trucks for them.
But i would split them to 2x60 engineers+3 trucks.