Electric Garage Talk: Hawaii Department of Transportation’s Fleet Electrification — Case Study
Case Study: Hawaii Department of Transportation’s Fleet Electrification
More than 20 years ago, in June 2005, Hawaii State legislators passed Act 216, requiring state agencies to evaluate their vehicle fleets and consider transitioning to electric vehicles. The intent was clear: assess feasibility and cost-benefit, reduce reliance on imported petroleum, and move Hawaii toward a more sustainable transportation future. With this mandate in mind, the Hawaii Department of Transportation began laying the groundwork for fleet electrification early.
Between 2006 and 2008, HDOT acquired several Ford Escape Hybrids, marking its first step toward vehicle electrification. In 2019, the department added four Chevy Bolts in preparation for a much broader transition. During this same period, Hawaii strengthened its policy framework through a series of legislative actions by establishing a fossil-fuel elimination policy, requiring state agencies to reduce greenhouse gas emissions, and granting procurement priority to zero-emission vehicles. These efforts culminated in Act 074 (HB 552), signed in June 2021 by former Governor David Ige, which mandates that all state agencies convert their light-duty fleet to 100% zero-emission vehicles by Dec. 31, 2035.
The HDOT Tesla Model Y Fleet.
Major Fleet Electrification
In 2021, HDOT took a major leap forward by partnering with Sustainability Partners under a service-based contract that allowed state and county agencies to acquire EVs and charging infrastructure on a per-mile cost basis. This model significantly reduced the upfront capital investment typically associated with fleet electrification.
Through the statewide fleet electrification contract, HDOT initially deployed 43 Tesla Model Ys and 43 Level 2 chargers across the islands.
“The idea behind the one-to-one ratio of EVs to Level 2 chargers was to avoid any charging issues,” said Robin Shishido, Deputy Director of the Highways Division at HDOT. “And if we expanded the fleet in the future, we wouldn’t necessarily need to add more chargers.”
That foresight proved valuable. Between 2023 and 2024, HDOT added 65 Ford F‑150 Lightnings and an additional Tesla Model Y, bringing the fleet to 113 electric vehicles. To support the expanding fleet, HDOT installed 24 additional Level 2 chargers at base yards statewide.
Robin Shishido, Deputy Director of the Highways Division at HDOT with a F150 Lightning at their NEVI chargers at Aloha Tower on Oahu.
The Cost and Savings of Electrification
Under the service contract with Sustainability Partners, HDOT was able to virtually eliminate upfront vehicle and infrastructure costs. Based on internal analysis, HDOT estimated average vehicle use at approximately 400 miles per month per vehicle. Factoring in vehicle procurement, outfitting, and charging infrastructure, the cost amounted to roughly $1.49 per mile, or about $600 per month per EV. Outfitting includes necessary equipment such as lift gates, radios, and light bars.
“We look at it as a fleet average,” Shishido explained. “One vehicle might only drive 200 miles a month, while another might drive 600. We pay the monthly usage fee based on that overall average.”
While fuel savings were relatively modest, HDOT quickly realized that maintenance savings were one of the most significant financial benefits. Traditional internal combustion engine (ICE) vehicles in HDOT’s fleet averaged about $2,500 per year in maintenance costs. By comparison, over the first five years of having their four Chevy Bolts, maintenance cost totaled just $55, and maintenance costs for the 43 Teslas were essentially zero during their first two to three years. Overall, maintenance costs are at least 50% less per year for EVs compared to their ICE vehicles.
The Human Fleet Navigation to EVs
With fleet electrification mandated by law, HDOT staff had little choice but to adapt — but the transition proved smoother than expected. Thanks to strategically deployed charging infrastructure and sufficient vehicle range, operational challenges were minimal.
Teslas in the fleet average approximately 180 miles of range, while Ford Lightnings provide 220 to 280 miles, depending on configuration. Typical daily driving for HDOT staff ranges from 40 to 150 miles, which largely eliminated concerns about range anxiety resulting in most employees preferring EVs over ICE vehicles.
“There was some initial hesitation from employees on the Big Island where crews have to drive far distances,” Robin noted. “But our engineers and inspectors quickly came to love the technology — the torque, the performance, the ease of use — so adoption followed naturally. And once we install our DC chargers at the base yards and NEVI sites, I think this concern will go away.”
HDOT operates a shared vehicle pool system, with no vehicles assigned to individual employees. The primary behavioral adjustment involved reminding staff to plug vehicles in after use and move them once charging was complete. Additionally, Tesla’s vehicle management platform allowed HDOT to place speed restrictions on vehicles, addressing safety concerns tied to the rapid acceleration of EVs.
Alignment with Hawaiian Electric
Although HDOT relies primarily on its own Level 2 charging infrastructure, Hawaiian Electric remains a critical partner. The utility has supported HDOT in charger installation planning and coordination, as well as in deploying NEVI-funded DC fast charging sites.
“In Maui, we had just 28 days to get chargers operational,” Robin recalled. “Hawaiian Electric’s crews worked in the rain to meet that deadline. Overall, coordination and day-to-day operations with them have been excellent.”
When answering the question “can Hawaii be a leader in commercial fleet electrification?” Robin said “Yes.”
“For light-duty vehicles, absolutely,” Robin said. “Short travel distances, strong charging networks, and grid capacity make EV fleets very feasible here. HDOT hasn’t needed any grid upgrades so far. Medium- and heavy-duty vehicles are more complex, but I’m confident we can get there.”
Robin also encouraged Hawaiian Electric to proactively engage property owners, helping them understand their available grid capacity so they can confidently plan for EV fleet expansion.
An HDOT Tesla Model Y fleet vehicle with a pavement data collection machine attached to it.
Tips for Future Fleet Electrification
For organizations considering electrifying their fleets, Robin offers simple advice: understand your driving patterns, identify charging windows, and match charger types to actual needs.
“If your workday runs from 8 a.m. to 5 p.m., your vehicle is parked for more than 12 hours a day. A Level 2 charger is usually sufficient — you don’t need DC fast charging. You also don’t need expensive consultancy studies. Just know your own operations.”
HDOT’s rapid deployment of 43 EVs and 43 Level 2 chargers set the stage for broader success allowing them to grow their EV fleet with ease.
With Hawaii’s clean energy goals drawing closer, fleet electrification is no longer a distant concept — it is quickly becoming standard practice across the islands.
Key Takeaways
HDOT’s fleet electrification journey offers a practical model for other organizations considering the transition to electric vehicles.
- Policy drives action: Clear legislative mandates (Acts 216 and 074) provided long-term certainty and accountability, enabling HDOT to plan and scale confidently.
- Innovative financing matters: A service-based, per‑mile contract model eliminated upfront capital costs and accelerated deployment.
- Right-sizing infrastructure is critical: A strategy of having one Level 2 charger for each EV minimized operational challenges and reduced the need for future electrical upgrades.
- Maintenance savings are substantial: While fuel savings were modest, dramatically lower maintenance costs delivered meaningful long‑term value.
- People adapt quickly with the right setup: Adequate range, reliable charging, and simple operating rules minimized range anxiety and eased staff adoption.
- Utility partnerships enable success: Close coordination with Hawaiian Electric supported fast charger deployment and long-term grid confidence.
- Hawaii is well-positioned to lead: Short driving distances, strong policy signals, and evolving technology make fleet electrification especially viable across the islands.
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About the Author: Jennifer Ecklund
