Ticket barriers may be the right choice in some circumstances (for example on the London Underground and suburban rail networks in London, and maybe in other major cities), but they are not necessarily the most effective weapon against fare dodging in all cases. On the LU and much of the London suburban network, they work well because most stations (in fact nearly all LU stations) are gated.
But where they are deployed at major stations in areas where most smaller stations do not have them, they only protect the minimum fare to and from the station where they are installed. They ensure that you have A ticket valid for A journey to or from that station, but not necessarily for the journey that you are actually making.
In many cases the installation of barriers seems to have led to a reduced effort by conductors to carry out regular ticket checks, although this may not be the only reason for them making less of an effort than they did in BR days or in the early days of privatisation. We have to ask ourselves, particularly in the case of long-distance services, what have the train operators achieved by going from "open" stations (i.e. without barriers) with a proper regime of regular on-train ticket checks to barriered stations with only very sporadic or non-existent on-train checks?
But where they are deployed at major stations in areas where most smaller stations do not have them, they only protect the minimum fare to and from the station where they are installed. They ensure that you have A ticket valid for A journey to or from that station, but not necessarily for the journey that you are actually making.
In many cases the installation of barriers seems to have led to a reduced effort by conductors to carry out regular ticket checks, although this may not be the only reason for them making less of an effort than they did in BR days or in the early days of privatisation. We have to ask ourselves, particularly in the case of long-distance services, what have the train operators achieved by going from "open" stations (i.e. without barriers) with a proper regime of regular on-train ticket checks to barriered stations with only very sporadic or non-existent on-train checks?