Final answer:
The sign that indicates there will be fewer lanes ahead is called a lane reduction sign. It provides advance warning to drivers about upcoming lane reductions and helps them adjust their speed and position accordingly.
Step-by-step explanation:
The sign that indicates there will be fewer lanes ahead is called a lane reduction sign. It is usually a yellow diamond-shaped sign with a black arrow pointing to the left or right, indicating that the number of lanes will decrease in that direction. This sign is used to provide advance warning to drivers so they can adjust their speed and position accordingly.
For example, if you see a lane reduction sign with an arrow pointing right, it means that there will be fewer lanes in the right direction ahead. This could be due to road construction, an exit ramp, or a narrowing road.
It's important to pay attention to these signs and merge into the appropriate lane early to ensure smooth traffic flow and avoid last-minute lane changes.