Night Light

Have you ever stepped off the sidewalk and into the crosswalk, only to realize, drivers don’t actually see you? With over 4,700 deaths and 66,000 injuries, annually, resulting from pedestrians crossing the street, crosswalk injuries and deaths continue to be the leading cause of harm to pedestrians. Night Light is an idea that can improve pedestrian safety while also bringing awareness to drivers, letting them know someone is entering into the street. Let’s make our neighborhood more walkable, not more dangerous.

Night Light Augmented Crosswalk

2016 // 1st Place Design Award - Science & Technology Showcase - University of Washington
2016 // Buerk Center for Entrepreneurship Business Plan Competition Finalist - University of Washington

6 weeks

Adam Riddle // James Rothenberger // Tristan Lee // Tim Wong // Collin Walker


This idea came out of a problem I was having - crossing the street at night and almost being hit several times. I started wondering why vehicles didn't see me. Was it the rain, or the low light levels, or were cars even paying attention to the task at hand? After some field research, I identified two aspects of the problem: 1. It's hard for a driver to see pedestrians crossing the street at night in low lit situations. 2. The crosswalk is difficult to see, especially when glare is strong on wet roads. From there, I did a competitive analysis to understand what was currently on the market and if there was an opportunity to create something more useful. Lastly, I conducted a series of interviews to see if there were any themes from either the driver or pedestrian's perspective. My assumptions were corroborated by these interviews about low light levels and difficultly viewing pedestrians.


Our hypothesis: Can we make a safer crosswalk by using lasers to augment a pattern on the ground that cars will see? The product could work by pushing a button (indicator to cross) which triggers a set of lasers to turn on, warning cars that someone is crossing the street and after a certain amount of time, the system turns off. As a team we generated dozens of ideas and built tiny models as a way of communicating our ideas to one another. The bottom set of images shows human-centered design principles to evaluate height, visibility and size.


The initial prototype was made with foam blocks in the Makerspace to get a sense of how large our crosswalk assembly would have to be. After researching standard code for such items, we proceeded with a height of roughly eight feet. This would be tall and prominent enough for both pedestrians and motorists. Given the time constraint, we worked as quickly as we could to create a full scale prototype since we wanted to test on actual intersections.

You can make certain assumptions about height, weight or size, but in the end, the only way to make sure something is going to work the way you think it is will be to physically build it – or at least build a portion of the thing that needs testing. For this reason, we built our prototypes at 1:1 scale so we could identify the challenges and limitations of each component. This was not only critical to the quick development of the product, but it was also the fastest way to test our concept, even when we had to redesign and rebuild large parts of the project.

We used two Arduinos with the xbee module to communicate when the button was pressed on either crosswalk assembly. Along the way, we also realized that not everyone would want a eight foot assembly in their neighborhood or a popular intersection. We created a second form of the assembly in parallel to address this.


The design not only provides a safe crossing area by outlining a crosswalk for pedestrians, but it also brings an awareness to drivers, letting them know someone is entering into the street. Because the entire system would be made up of a metal pole, an Arduino Breadboard, and a series of lasers, it’s requires almost no maintenance and is very inexpensive to build / replace / maintain. In fact, running a laser for 8 hours in a row is less than one dollar. The crosswalk pattern is visually eye catching because of its color, but also because of its detail. It can be made very accurately and precisely, with very low energy and will work no matter what the weather conditions are: pitch black, rain, snow. However, this idea shouldn’t be deployed at every crosswalk. This idea is location specific, depending on traffic flows, lighting quality, walkability, and previous accidents to help the worst cases.