Final answer:
When the entrance lane is too short for proper acceleration, it is safest to stop and wait for a large gap in traffic before entering the highway and accelerating quickly to match the prevailing speeds.
Step-by-step explanation:
If the entrance lane is too short to allow acceleration to highway speed, the best course of action is to stop and wait for a large gap in traffic, then enter the highway and accelerate quickly. It is important to ensure that you have enough space to merge safely and accelerate to match the speed of highway traffic to avoid potential collisions. Merging into highway traffic as soon as possible without sufficient acceleration could be dangerous, and looking for the next entrance ramp might not always be a practical or safe option.