A B737 crew reports that a Regional Jet taxiing at a high speed with its landing lights off in freezing rain failed to slow or yield to them and so nearly collided on ORD taxiway 'R.'

Narrative

We were cleared to Runway 28. As we taxied out and started to enter Taxiway R; a Regional Jet was proceeding southwest on Taxiway B approaching Taxiway R from our right. We slowed and then stopped as the RJ made the left turn onto Taxiway R nose-to-nose with us. Our Ground frequency was too congested for me to get a radio call to anyone. I checked and the RJ was taxiing with their landing light off and ours was still on. The RJ continued without yielding making another left onto Taxiway A. I was gravely concerned about an impact between the 2 aircraft. I finally got a radio call to Ground and filed a verbal report with them. The RJ was on the Ground inbound frequency further complicating safe operations. The RJ's wingtip passed dangerously close to us at an inappropriately high speed. Further; Air Carrier X and other airlines have not adopted FAA recommendations (should be mandatory) of using the taxi light during ground operations to show movement or intention to move. These should be mandatory SOPs. We did use our landing light appropriately and the RJ did not. Further; different Ground frequencies for aircraft taxiing in close proximity may be standard at ORD; but it significantly degrades safe airport operations. Most congested airports do not use this procedure but instead use different frequencies geographically around the airport. So; lack of SOPs; lack of ATC mandatory taxiing procedures; ATC ground frequency procedures; and the RJ's blatant disregard for safe operations (regardless of any clearance he might have had) all contributed to this incident. We were the only link that broke the chain of what could have been a major ground accident.