This increased the capacity of the above-water portion of the facility to four lanes, facilitated needed repairs, and helped insure against a total closure should a trestle be struck by a ship or otherwise damaged (which had occurred twice in the past).
The expansion of the facility's above-water portion to four lanes, repairs that were made, and measures taken to prevent a complete shutdown in case of damage to a trestle (which had happened twice previously) are all described here.