Mileage reporting prototype for Washington’s upcoming road usage charge

Designed 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.

  • Execution Duration: March — June 2017
  • Role: UX/UI designer; Print/editorial designer
  • Credits: Alex Gilbert, Michael Fernandes, Molly Fallen
  • Sponsors: Washington State Transportation Commission (via UW HCDE) with support from D'Artagnan Consulting and The Mobility Center
  • 2017 UW College of Engineering Capstone Design Project Grant
  • 2017 Smartphone Innovation Challenge Award of Excellence
  • 2017 Smartphone Innovation Challenge Certificate of Achievement
  • 2017 UW HCDE Best in Show
Tongle glipse of final output

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.

As final deliverable, my team proposed Tongle, an app that pairs with an external device to ensure fair and convenient mileage recording. It has three key concepts:

1. Record locally. Sync with 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.

Tongle final output pt 1
Sample view of of synced My Trip data

2. 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.

Tongle final output pt 2a
Demo of viewing a trip detail and submitting a contest for an incorrect mileage record

3. 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 final output pt 3
Tongle app with GPS enabled vs disabled

Design Process

Building citizen-centered design

To end with these concepts, our team sat down with drviers 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.

Tongle PD workshop 1
Our team and WA drivers
Tongle value affinity analysis
Affinity analysis of user needs found from the user research
Past RUC solution analysis
evaluations of past design solutions using the user needs
PD workshop 2
design exercises and ideation with WA drivers
design ideation 3
team whiteboarding on app interactions

Developing Visual Identity of Tongle

Friendly, Trustworthy, and Efficient

My secondary roles included creating 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.

Tongle style guide
Tongle quick style guide

Presentation and Awards

We presented our project at the 2017 HCDE Capstone Open House, the biggest annual public event held by the department of Human Centered Design & Engineering and 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.

Tongle poster
Project presentation poster
project presentation at the HCDE Open House
presentation at 2017 HCDE Capstone Open House
project presentation at the Smartphone Innovation Challenge
presentation at Smartphone Innovation Challenge

"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 how much my team has accomplished in 10 weeks, I wish we got chance to talk with the developers and iterate our prototype based on technical feasibility. I would also document the design system for better design consistency.