Sen. Pat Roberts (R-Kansas) warned of a coming “train wreck” when enrollment begins in ObamaCare insurance exchanges this fall in the Republican weekly address.

Roberts, an outspoken opponent of President Obama’s healthcare reforms, said that important questions remain before the exchanges, part of what he called a “massive federal government takeover,” go into effect in October.

“Too little is known about the exchanges. The fear is that only the sick will pay to join the exchange without young healthy people to foot the bill, then all costs will further skyrocket,” Roberts said.

Republicans and Democrats alike have complained that the White House hasn’t done enough to inform the public about the law’s advantages prior to its upcoming rollout.