This page provides links to some of the popluar model railroad hobby forums. Forums listed are those that appear to have a substantial number of posts per days. What is substantial? That is my own subjective judgement, but a forum that does not see in the 8-10+ posts pretty much every day and many more on some days will most likely not be included in the list.
Model Railroader Forums - Active forum associated with Model Railroader magazine. forum participation does not require a magazine subscription.
Model Train Forum - Active discussion site that bills itself as the complete model train resource.
MyLargeScale.com - Active discussion forum focused on G scale.
New Railway Modellers Forum - Discussion forum focused on railroad modelling advice for beginners.
nScale.net - Extremely active forum focused entirely on N scale model railroading.
O Gauge Railroading Online Forum - Very active discussion forum focused on O scale model railroading.
Railroad Forums - Very active forum discussion site covering a wide variety of railroad topics for ailroad modelers, railfans, and enthusiasts.
Railroad Line Forums - Active discussion site with specific forum areas on a wide variety of model railroading topics.
Railroad.net - Large discussion forum on thousands of railroad topics.
The Railwire - Active discussion forum covering a wide variety of model railroading topics.
TrainBoard - Somewhat active site tht bills itself as the Internet's Original train forum.
TrainOrders.com - Long time active discussion forum organized around geographic areas and tpes of railroads.