Officials overseeing Honolulu’s rail tax revenues continue to be confounded by the project’s revenue collection, whose performance has see-sawed from quarter to quarter.  

Rail officials announced Monday that for the months of July, August and September the transit project will receive $64.8 million from Oahu’s general excise tax surcharge to fund construction. That’s $8.3 million more than what the Honolulu Authority for Rapid Transportation had expected to take in for the quarter, based on the project’s financial plan. 

It also represents a positive swing when compared to the equally negative swing in the previous quarter. For April, May and June GET revenues were exactly $8.3 million below what was projected in the financial plan, according to HART. 

In the two quarters before that, rail’s GET revenues came in more than $1 million and $9 million above what the financial plan had projected, respectively. State Department of Taxation officials have pointed to a lag in processing tax returns as a key reason for the swings. HART officials, meanwhile, said Monday that they still don’t fully understand what’s causing the swings. 

Despite all the fluctuating, GET collections for rail remain overall $30.5 million below projections. HART officials further expect that gap in collections to swell to $100 million by the end of construction. 

Along with soaring local construction costs, HART officials have pointed to the lag in revenues as another factor in the project’s massive budget shortfall. The 20-mile, 21-station system was expected to cost $5.26 billion but costs have since spiked to an estimated $6.57 billion. 

HART reports that $1.58 billion in state rail tax revenues have been collected since Oahu’s 0.5 percent surcharge began in 2007. 

Rail officials acknowledge they still don’t know what the final price tag will be to build the transit system. The city doesn’t expect to have all rail’s remaining construction contracts signed until next summer, and the project isn’t slated to be finished until 2021.