If there is a long straight and today you would put a chicane. You can instead add electronically controlled zone where for example the car has to slow down to 60 kph at some point within given 100m zone. You'd get sound or a light that turns on once you hit that speed and after that you are free to accelerate. Obviously there would have to be small penalties for either not slowing down enough or for not slowing within the given zone.

It sounds more artificial than chicanes from hay-balls but on the positive side:
- no damage to car from hitting them
- no unfair situation when the balls get moved
- no need to address penalties for moving the balls
- no need to have people on site to both move the balls and hand out penalties to drivers

So yeah don't get all the screaming going on here. Obviously it's better to have stages that don't need slowing down.