Senators Charles Schumer and Richard Blumenthal touted proposed railroad safety legislation Sunday that calls for cameras in and outside engineer cabs and a mechanism to automatically slow or stop a train.

The Senate bill, which is expected to be introduced Monday, aims to improve railroad safety after recent crashes, such as the December 2013 Metro-North derailment in the Bronx that killed four and injured dozens of others, and enable regulatory agencies to levy heftier fines for violations, the lawmakers said.

"With all of these derailments and other mishaps, it is obvious that we need a dramatic overhaul when it comes to rail safety -- both passenger and freight," Schumer (D-N.Y.), said Sunday at Grand Central Terminal in Manhattan during a news conference with Blumenthal (D-Conn.). Under the terms of the proposal, railroads nationwide would be required to implement positive train control by December 2015 or be fined by the Federal Railroad Administration. The safety mechanism is designed to automatically stop or slow a train.

Blumenthal said the mechanism would have helped prevent the fatal Metro-North derailment. The engineer dozed off as the train sped at 82 mph around a curve where the speed limit was 30 mph.

The train careened off the tracks, ejecting passengers and overturning in thick brush.

"Riders on Metro-North and all of our commuter and passenger railroads have to be assured they are not riding into the unknown, that they have security and safety on the nation's railroads," Blumenthal said.

He said $3 billion would pay for the new technology and equipment, among other improvements.

Penalties would increase from $25,000 to $100,000 for any safety violations and up to $1 million for aggravated violations, he said. "The watchdog agencies have to have bite, not just bark," Blumenthal said.

The proposal aims to put into law many of the recommendations of a Federal Railroad Administration report assessing the safety and training plans and practices of Metro-North, and the recent findings of the Metropolitan Transportation Authority's blue ribbon panel.

The panel criticized Metro-North for a lax safety climate and problems in track maintenance.

Schumer said the proposal calls for more frequent track inspections.

Last week the MTA said it was considering putting cameras inside passenger cars after plans to put cameras in engineering cabs.