Context: Disadvantages of electric traction include high capital costs that may be uneconomic on lightly trafficked routes; a relative lack of flexibility since electric trains need electrified tracks or onboard supercapacitors and charging infrastructure at stations; and a vulnerability to power interruptions. Different regions may use different supply voltages and frequencies, complicating through service. The limited clearances available under catenaries may preclude efficient double-stack container service. The lethal voltages on contact wires and third rails are a safety hazard to track workers, passengers and trespassers. Overhead wires are safer than third rails, but they are often considered unsightly.

Question: What issue can complicate electric railway service?
Answer: different supply voltages and frequencies,

Question: What is a safety hazard to track workers?
Answer: voltages on contact wires

Question: What is a safer alternative to third rails?
Answer: Overhead wires

Question: Why overhead wires are not being widely used?
Answer: considered unsightly.

Question: Advantages of electric traction include?
Answer: Unanswerable

Question: All regions use the same supply voltages and?
Answer: Unanswerable

Question: Lethal voltages on contact wires and third rails are non a safety hazard for whom?
Answer: Unanswerable

Question: Third rails are considered safer than overhead wires, but are considered what?
Answer: Unanswerable