Positive Train Control?

[Baldy's Boss]

Is there a way to simulate PTC?

Perhaps a railtype with crash-avoidance protocols that costs extra?
Maybe have all track tiles between two signals of identical type treated as also having signals of that type?

[Sylf]

Maybe have all track tiles between two signals of identical type treated as also having signals of that type?

Why not just place signals on every tiles then? This will 1) increase the construction cost and 2) increase the maintenance cost.
The only time a train collides with another train is when the constructor (player) makes a mistake. Train protection systems are normally placed to prevent disasters when operators (train engineers) make a mistake or are stricken with unforseen events (sickness etc).

[FLHerne]

OpenTTD already behaves as though there's PTC at every signal. Trains stop instantly at every red, and collisions never occur unless you manually tamper with the system (remove signals or force trains past them).