What is the maximum speed combined trains can travel at?

The correct answer highlights that the maximum speed for combined trains is set at 15 km per hour. This speed limit is typically enforced to ensure safety during operations involving multiple train units, especially in circumstances where they are coupled together, as this can affect handling and braking performance.

Operating at this slower speed allows for more controlled movements, minimizing the risk of accidents or mechanical failure when trains are combined. Furthermore, the lower maximum speed can help maintain stability and prevent undue stress on the rolling stock, which is particularly important in fault-finding scenarios where equipment might already be experiencing issues.

In the context of rail operations, safety regulations and operational efficiencies are paramount, which justifies this speed restriction for combined trains. This consideration helps ensure safe travel and protection of both the infrastructure and the crew involved.