How to pin down location of views/shared directory ?

for images you should use <%= image_tag('vehiclesButton.jpg') %> if
your image is in images directory and it will automagically match the
url where ever you are in your app. If you use something like <img
src='someimage.jpg'> then it will have some path related problem at
some point of time.

if you want to make your image a link then you can either use link_to
image helper or simply <%=
link_to(image_tag('vehiclesButton.jpg'), :controller
=> :controller_name, :action => :action_name) %>

hope this helps