What action can help prevent traffic jams?

Keeping opposing lanes open can indeed help prevent traffic jams by allowing for a smoother flow of vehicles, particularly in situations where congestion might occur due to vehicles blocking intersections or merging lanes. When opposing lanes are accessible, such as in situations with two-way traffic, it enables vehicles to navigate past one another more effectively, thereby reducing bottlenecks. This can be particularly valuable in areas where there are breaks in traffic or where vehicles may need to yield for one another.

In contrast, while reducing speed in congested areas can help maintain safety and prevent accidents, it often doesn't address the root cause of congestion and might exacerbate the delay. Using alternative routes can alleviate traffic in specific areas, but it doesn't necessarily affect overall traffic flow in a broader sense. Installing traffic cameras might help monitor traffic patterns and enforce laws but does not actively prevent traffic jams. Each of these actions has its place in traffic management, but keeping opposing lanes open can provide immediate assistance in facilitating vehicle movement and improving traffic conditions.