Chester is at the bottom of a hill, on a curve, and looks to have decent access to US-20. Apparently all the trains have to slow down there anyway. There is also a large <=1850 wooden station, the only Western Railroad station not replaced or moved.https://www.chesterrailwaystation.net/History.html
Ten seconds with Google -
2020 population of Chester MA: 1,228
2020 population of Westfield MA: 40,834
Yup, Chester is clearly the logical choice between the two here... NOT.