Accident Alerts

So Blaurb and I are driving from Wellington to Napier, New Zealand, and we drive this curvy road behind this lumber truck, and I visualize this scenario, where the straps on the lumber give, and logs start falling onto the road, and I'm forced to swerve and dodge these huge logs coming at me. Then I thought about accidents, and how it could lead to a pile-up of cars since I had cars following closely behind me.

It would increase safety if cars came with accident alerts that created some huge display to indicate an accident has occurred. The system would activate upon a serious collision (such as one that triggers the airbag). Cars following behind would be able to see that an accident has occurred, and slow down well before they reach the site of the accident (and the ensuing pile-up of cars). This could be pop-up emergency signs, flares (thanks Blaurb), or anything else that could be universally recognized as an accident sign. I think such a system, made standard on cars, would lead to increased road safety.