Comparing Honolulu’s Elevated Rail to Express Lanes, Based on Energy and Environment – Part 2 in a Series

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– The National Transportation Policy Project (NTPP) sponsored by the Bipartisan Policy Center produced Performance Driven: New Vision for U.S. Transportation Policy.


Let’s analyze how 20 miles of rail with 21 stations and 10 miles of High Occupancy and Toll (HOT) lanes would score in an application in Honolulu based on NTPP Goal 2, which is Energy and Environment. This goal has two metrics, petroleum consumption and CO2 emissions.

In order to reach a bottom line, the best alternative for each goal will receive a score of 10 and the second best will receive a relative score between 0 and 10.

Brief System Descriptions

The system descriptions for RAIL and HOT LANES for Oahu can be found in the first article of this series by clicking here.

Petroleum Consumption

RAIL: While nationally rail may be powered by a mix of coal, hydroelectric and nuclear power, on Oahu over 95 percent of electric power is generated by burning oil and coal. Unfortunately during off-peak hours trains tend to run nearly empty. They draw a lot of oil-based electricity power for very little transportation work. Also the rail will reduce car trips on Oahu by 1.1 percent only, so oil dependence for cars will not be reduced. Worse yet, congestion with rail will be terrible during construction and after it opens. Overall petroleum consumption and dependence will be high with rail. Score = 3.

HOT Lanes: They have the advantage that from day 1 they can serve hybrid buses, hybrid cars and electric cars. The HOT lanes can be constructed to provide under-the-roadway induction conduits so electric buses can run on them. Electric buses will draw oil and coal based electricity on Oahu. However, electric cars and plug-in hybrid cars can easily be charged at home or work by solar panels and mini-windmills as shown in this sample of two installations near the UH-Manoa.

House near the University of Hawaii at Manoa with solar panels.
House near the University of Hawaii at Manoa with a mini-windmill.

These devices provide an opportunity for distributed renewable energy, which is heavily incentivized today: $7,500 federal tax credit and $4,500 Hawaii tax credit for an electric car; 30 percent federal tax credit and 35 percent Hawaii tax credit for solar panels; $2,000 federal and state credit for a car charger at home (actual cost of the charger to the user is ~$200.)

The U.S. and Hawaii energy policy favors electric car purchases not fixed rail. Construction of 10 miles of HOT lanes is only one third as disruptive as rail and after they open, congestion along the Waikele-to-downtown corridor will improve by over 25 percent. Score = 10.

CO2 emissions

RAIL: Unlike the mainland where hydro and nuclear power accounts for almost 30 percent of electricity generation (and oil accounts for about 1 percent), Oahu’s electricity is almost entirely based on oil and coal so the CO2 emissions of rail on Oahu will be terrible because they are proportional to oil dependence. Severe congestion during rail’s construction and its minimal benefit afterwards result in a highly polluting final outcome. Strong incentives for solar power roof-top deployments affect individual users and do not lessen the rail’s dependence on oil-based electricity. Score = 2.

HOT Lanes: The future of urban transportation is “electric automobility” based on the incentives mentioned above. The Oak Ridge National Laboratory (ORNL) demonstrated that electricity production from wind is best at night, but that is a time that society needs electricity the least … except for thousands of electric cars being charged with wind energy overnight. ORNL has identified this as a synergy that may make wind power generation cost-competitive. HOT Lanes are perfectly positioned to serve electric cars, vans and buses and dramatically reduce CO2 emissions. HOT lanes dramatically reduce CO2 pollution from day 1 by reducing corridor congestion by 25 percent or more. Score = 10

Based on the Energy and Environment goal and its two metrics, HOT Lanes on Oahu score 20 points and Elevated Rail scores 5 points.

Stay tuned for one more installment based on NTPP Goal 3, and an overall summary.

Panos Prevedouros, Ph.D., is a professor of civil engineering at the University of Hawaii and past candidate for Honolulu mayor. He can be reached at





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