If you've ever driven on icy roads, you'll know just how treacherous they can be. How do road crews make the roads safer for travel? You may have seen them spraying a solution on the roads prior to a big storm, but what exactly is in that mixture and how does it help? With the extremely cold weather conditions across the country recently, this would be a timely topic for your students to explore.
I grew up in New Hampshire, and I can remember wondering why crews spread salt and sand on the roads. As it turns out, the salt lowered the freezing point of water which kept it from freezing at 32 degrees, and the sand made the roads less slippery providing traction for the vehicles.
Investigating Other Solutions
Recently scientists have been exploring other options that are not only environmentally safe - they actually save money. A few days ago I read an article with information about various solutions that seem to work even better than salt water. Would you be believe some states are using substances like cheese brine and a solution made from beets?
I wonder what other solutions might work to make roads safer in winter? A fun follow up to the Icy Roads Investigation above would be to have students repeat the Icy Road Investigation using a different solution to see how the new substance affects the results.
Know-Wonder-Learned Chart Freebie
Even if you don't live where winter weather is a problem, your students have seen enough movies to know that snow and ice on the roads create dangerous driving conditions. Exploring how roads can be made safer is a timely science topic, and your student are sure to enjoy this hands-on activity and research project.