There are several reasons that a street-level rail system would not be feasible at this point of the Honolulu rail project, including:

• One significant reason is that the rail system is powered via a “third rail”, which is literally a separate rail that runs alongside the tracks. The trains receive electricity from the third rail, which carries 750 volts of electricity. Having a street-level system would require significant barriers to protect the public from the dangers of the third rail, which is currently achieved with the elevated guideway system.
• Another reason that a street-level system would be problematic is that the trains are expected to have approximate 6-minute headways (the time between trains) during peak hours of operation. That means, for a street-level system, certain intersections all along the route would need to be closed to traffic and pedestrians at least every 6 minutes for a train to pass. This would create additional traffic congestion on our streets that is avoided with the elevated guideway.