ABSTRACT
Impacts with narrow fixed objects such as poles, trees, retaining wall ends, and other obstacles require special consideration from the reconstructionist. For example, real-world poles may be fixed (or not, if they are mounted on a slip base), but they are not infinitely rigid. Nor are they infinitely massive. They can be separated from their base, pushed over in the ground, or totally or partially fractured (splintered). While they are not infinitely massive, their mass can be significant relative to that of the vehicle. Trees usually are not broken unless they are fairly small, but they can bend and sometimes recover. Trees can dissipate energy aerodynamically if their foliage whips about in the air, and by vibrating. Trees are living things and can grow and heal; some can even straighten out somewhat after the accident.
