Will there be any follow-up legislation to PTC in the next few years? Or is the original legislation that Bush passed stringent enough with no need for further guidelines?

Predicting what Congress will and will not do sounds like a proposition that requires a crystal ball.

Remember that the Rail Safety Improvement Act of 2008 was enacted into law barely a month after the Chatsworth, California disaster on September 12, 2008. Several of the mandates in the act (like the changes to the Hours of Service Act) had long been debated in Congress, but there was no certainty that they would be passed by Congress or signed into law by then-President Bush.

After Chatsworth, this all changed, and the RSIA of 2008 mandated PTC on a large part of the rail network, made sweeping changes to the Hours of Service Act, and a whole lot more. Little of this could have been predicted before Chatsworth.