The Speedy Trial Act of 1974, 18 U.S.C. §§ 3161–3174, generally requires that Federal-court trials in felony cases take place within a short time, or the case will be dismissed. In practice, this means that criminal cases reach trial far more quickly than civil cases and that civil cases can be delayed for long periods while waiting for the criminal caseload to diminish.
Occasionally, there are extreme cases resulting in the declaration of a judicial emergency suspending the provisions of the Speedy Trial Act for a limited time. See, for example, In re Approval of Judicial Emergency Declared in District of Arizona, 639 F.3d 970 (9th Cir. 2011).
In the ordinary situation, the priority for trials of criminal cases simply means a delay in resolving civil cases. Judges work very hard to speed cases along, but realistically there are limits to what they can do.
Arbitrators do not handle a criminal docket and can focus all their efforts on reaching a speedy resolution of the civil disputes they are asked to resolve.