All the commercial trucks use a switch and a set of warning lights. I like the Isuzu one the best so far.
No lights - all is normal.
Green light - all is normal but performing a passive regen (no fuel added to light DOC).
Yellow light - Vehicle needs to be brought up to speed to passively regen or pulled over and switch engaged to perform parked regen.
Orange light - vehilce needs to be pulled over and parked regen performed ASAP.
Red light - regen not permitted due to saturation of DPF to perform a regen. This light in conjuction with the check engine light and a 30% horsepower derate means you screwed yourself and need to take to dealer to have a forced regen performed.

International uses a similar system, but uses a "regen" symbol which means you need to drive it faster or harder, or perform a parked regen. It has a "hot exhaust" symbol to tell the driver the exhaust is hot because it is performing a passive regen. Then a red stop engine light, horsepower derate occurrance and emissions system warning light (differenct from the check engine light).

On these systems, you can't just hit the button while driving and perform a regen. It performs a parked regen which better cleans the DPF because it can add fuel at a better rate and accuracy without the interference of driving conditions.

That automatic regen is annoying and I think the warning light system better lets the driver know what needs to happen and when.