Tongle
Pilot solution for Washington State's future infrastructure tax system
Tongle is a cross-device prototype for the Washington's proposed Road Usage Charge policy. It records mileage and syncs the data with a paired phone app, which allows drivers to view, contest, and pay for their road usage. Our project has won several awards along with a grant.

The Challenge
How can road infrastructure be funded more inclusively?
With an increase in average fuel efficiency, funding roads with a gasoline tax is no longer sustainable. Washington State has proposed a per-mile tax based on miles driven, called the Road Usage Charge. In order to accomplish this policy, the state needs a way to verify the numbers of miles driven.
The Solution
Tongle, a cross-device system that records mileage and syncs the data with mobile
As a final deliverable, my teammates and I proposed Tongle, a cross-device system that records mileage and syncs the data with a paired phone app, which allows drivers to view, contest, and pay for their road usage.
Record locally & sync with the phone app. Save people's phone batteries
The external device, plugged into a car's OBD-II port, records and stores a car's trip data. The ability to locally record mileage prevents large battery consumption as our research found that drivers don't want their batteries to drain due to the RUC mileage meter.

Sample view of synced My Trip data
View, verify, and pay on your phone. Apply the proper per-mile rate
The coupled app allows users to view, contest, and pay for their road usage. They can also set up auto-payment cycle and method for their convenience.

Drives can view a trip detail and submit a contest for an incorrect mileage record
Retain control of privacy settings. Respect drivers' privacy
Some drivers negatively perceived mileage recording as “being tracked by the government.” To gain their trust, our design lets users enable GPS for specific trips and protect their privacy.

Tongle app with GPS enabled vs disabled
The process
Building citizen-centered design
To end with these concepts, our team sat down with drivers from all over Washington State. Over the span of workshops, we together explored and evaluated different RUC methods. Our participants' perspectives revealed a core set of needs to be addressed in our designs. We used rapid prototyping method to build and iterate our design solution that sought to effectively address the tensions between those needs.

Our team and WA state drivers had the span of workshops exploring and evaluated different design solutions

We analyzed and grouped the user needs found from the user research. Some of the top values that WA drivers care are: accountability, privacy, convenience, and fairness.

We then evaluated past design solutions using the user needs found in the affinity analysis.

In the next session, we shared our research and facilitated design exercise in which drivers ideated solutions based on the user needs.

After the design exercise, our team gathered to narrow down and refine design solutions.
Defining Visuals
Friendly, trustworthy, and efficient
My secondary roles included developing a style guide and visual identity of Tongle. I aimed to create a visual look that conveys friendliness, trustworthy, and efficiency because many citizens tended to perceive tax systems as something complicated.

I chose Teal and green colors inspired by Washington's evergreen; Roboto, a neo-grotesque sans-serif typeface, to convey formality.
Presentation & Awards
3 awards and 1 project grant
We presented our project at the 2017 HCDE Capstone Open House, the biggest annual public event held by the department of Human Centered Design and Engineering. We also presented at the Smartphone Innovation Challenge held by the Mobility Innovation Center, the Washington State Transportation Commission, and select consulting team members.
Our project received positive reactions from both general public and our sponsors/clients. Along with a grant from the UW College of Engineering, we were awarded the Best in Show out of 14 HCDE undergraduate projects and Excellence out of 4 multidisciplinary (2 HCDE, 1 Informatics, and 1 Electric Engineering) capstone teams.

Project presentation poster

Presentation at Smartphone Innovation Challenge

Presentation at Smartphone Innovation Challenge
Reflection & Next steps
“The participatory design approach was really exciting.... Instead of government concocting a solution, and then trying to persuade others to logic of your solution, they worked with users throughout.”
— Jeff Doyle, a Partner at D’Artagnan Consulting
I want to give thanks to our sponsors and research participants for making this project possible. First time being introduced participatory design, I had opportunity to design with stakeholders throughout the project and share design thinking with non-designers.
While I am proud of how much my team has accomplished in 10 weeks, I wish we got chance to work with the developers and iterate our prototype based on technical feasibility. I would also like to look into Material Design or iOS guideline in order to better understand mobile design guidelines and improve visual design (visual hierarchy, more accurate usage of accent color).