Here's why solar roadways loving suck
SnowThere's no way that the solar panels could actually generate enough heat to melt snow. Heating one 1 liter of water from 10 °C to 30 °C needs ~84 kJ. It'd be impossible for solar panels to generate this amount of energy to melt all the snow on the roadway. We have snowplows for a reason, so we don't have to spend trillions of dollars on melting all the snow in America. Also, glass is slippery enough, wet glass might as well be an ice rink for cars.
Lighting the roadWe have cats eyes and car headlights. We made these specifically so we wouldn't have to light up every single piece of the road when nobody is using that particular part of the road. So, we light up the most important and immediate part of the road, the part that is in-front of the car.
Glass panelsYou could never emergency stop an 18 wheeler on glass. It is simply not going to happen. The "testing" they did for traction requirements was done with a tractor on a driveway. Also, since the panels are separate units, there is going to be an issue with differential loading, in which panels will come loose.
Radical tron LED lightsYou cannot see LED lights in bright daylight. Also, why the forget would we need to have dynamic road lines on highways that have remained the same for decades? Also, light pollution is a big enough problem on Earth right now.
CostThe glass required, the glass ALONE, would bankrupt America. This is not including LED, wifi, solar panel and maintenance costs.
Power transportSolar roadways send electricity underneath ALL ROADS IN THE USA. Here is a map of the U.S. powergrid, which is already a huge pain in the ass:

Now imagine running these transmitting cables underneath EVERY SINGLE ROAD IN AMERICA
/rant over
sorry, i just get really fired up that these guys received +$1,000,000 USD and it'll all probably go to stripclubs and beer