opencv - Haar Cascade Classifier -

i newbie opencv.

i have read lot of articles haar classifier. not getting 1 information kinds of object haar classifier should used.

for project, need detect railway line. have trained haar classifier small sized samples of rail line , created own detector, not detect properly.

in maximum cases detects object environment rather rail line. that's why, still confused if use of haar classifier proper way rail line detection or if not, classifier should used.

thanks in advance.