is there any newgrf with straight - or | roads ?

[MlemandPurrs]

its fundament is already there, in the game used for train tracks, so can we have straight horizontal or vertical road lines.
if i may further the idea can make road train logic and create an seperate lorry station object with train station's way of building, and then have 'road train's that can carry one or multiple 'wagon's behind that require to drive through such an 'road station' for load/unload.

[FLHerne]

It's impossible to make such a NewGRF.

Long articulated road vehicles already exist, in the 'HEQS' set among others, but only require a single drive-through station.

[kamnet]

No, it's actually not fundamentally there. Roads and rails are two entirely separate beasts in OpenTTD.

There previously exists a patch which introduces diagonal roads, and some graphics drawn for it, but it's not complete, it was glitchy and ultimately abandoned by its developers.

[Alberth]

its fundament is already there, in the game used for train tracks, so can we have straight horizontal or vertical road lines.

That's what you'd think at first. If you want to understand why it's not there, please try to draw such roads in the same spirit as train tracks, as well as the connections to the roads we have now onto the grid, such that you get nice repetitive patterns.

Keep in mind you need enough width for a road for 2 vehicles in opposite direction.

Good luck!