JAMAICA, Queens (PIX11) — Another batch of service changes rolled out on the Long Island Rail Road on Monday morning, as fine-tuning continues after the start of full service to Grand Central Madison.

Effective Monday, four trains will be rerouted from that new East Side transit hub to Penn Station. Additionally, four trains serving the Ronkonkoma branch during the morning peak will have their routes extended to two additional stations.

The changes come as tweaks continue to LIRR service since the Grand Central Madison launch. While some travelers have hailed the increased access between Long Island and Manhattan’s East Side, many others have said that their commutes have been negatively impacted by the change, with significant crowding and tight transfers among the issues.

In response the LIRR announced a slew of service changes last week, now followed by Monday’s further updates. And even after the latest changes, the schedule continues to be a work in progress, with Catherine Rinaldi, the LIRR’s interim president, recently calling it a “very dynamic process.”