This is a classic example of the outcome of unforgiving roadside environment. Due to the unforgiving roadside, regardless of whatever reasons for any vehicles to swerve to the roadside, severe accidents will likely happen.
Definition of unforgiving roadside environment: there are occurrances of fixed objects such as trees, utility poles, or other immovable objects located only a few feets beside the road.
Possible reasons for vehicle to swerve or skidded to the roadside; avoiding from hitting other objects on the road such as children suddenly crossing the road, animals such as dogs suddenly crossing the road, avoiding from colliding with other out of control vehicles, reckless driving, etc.
In this case where an ambulance transporting a pregnant mother involved in an accident by crashing into a tree when the driver was trying to avoid hitting a dog that was crossing the road at Mile 9, Jalan Penrissen.
The challenge to provide a more forgiving roadside environment is a very challenging task due to constraints in term of funding and legislative issues.