Anti-Climbers were deleted from more modern designs, especially light rail and rapid transit applications that were exempted from federal regulation; ostensibly to reduce weight and therefore operating costs. But just because you can do something, in no way means you should.

In my opinion, that also reduced the safety of rapid transit in general. At least when compared to the safety quotient attainable, when you do all that CAN be done to protect passengers; doing only some things but not all, can never be considered as safe.

Of course, the federal exemption had more to do with politics than it had to do with the laws of physics, or common sense. Many believed that the commerce clause of the Constitution permits the Federal Government to regulate only commerce that crosses state lines. In fact, it has often been referred to as the "Interstate Commerce Clause". Unfortunately, regulation at the state level has been spotty at best, and totally ineffective or non-existent generally.

Indeed, I used to believe in the "Interstate" limitation too. But recently, while studying for an assigned report, I discovered that the Constitution does not even mention the word "Interstate" at all - not anywhere. It simply grants Congress the power to "regulate commerce among the states" - a much broader wording indeed!

In any event, after several recent fatal rapid transit collisions, caused both by human error and by machine error (hazardous failures in PTS like automatic controls); there is a move in Congress to extend federal regulations to both rapid transit and light rail, similar to that now imposed upon the railroads by the F.R.A..

While there seems broad consensus about such regulation in general, they still wrangle and fuss over just how similar the regulation will be, and whether the F.R.A. will directly regulate, or whether it will be via the F.T.A., as client to the F.R.A., and also just how much of a roll the states will retain. So it just sits - going nowhere.

Ain't politics just GRAND! --- Even though Congress has finally woke up to a stupid absurd double standard between transit and railroads (the laws of physics are the same for both); public safety still takes a back seat to infighting fiefdoms of our government.