The other day I alluded to the posted grade of a hill between New Hope and Wrightstown, PA. In the course of trying to figure the actual grade of the hill myself, I found Measuring the Hilliness of Routes which is part of Ken and Sharon Roberts’ Bike Hudson Valley website. This page contains the formula for calculating the grade of a hill as well as something called a “hill index” which is an attempt to put a number on the average hillyness or steepness of a cycling route.
You’d think that a Rensselaer graduate like me would be able to accurately estimate that a hill that rises 257 feet in a mile (courtesy of my Garmin Forerunner 201) would be a 4.8% grade. I wanted to make sure I was computing this correctly because I thought the sign on the other side of the road indicated that the hill was even steeper.
I could have sworn that I saw a sign on PA 232 that said the hill going down into New Hope was 9%. Was I so out of it as I reached the top the climb of the year that I couldn’t read the sign correctly as I glanced over my shoulder?