A successful underground project is one where relationships are strong, the objectives as understood by each party are met or exceeded, and the work product serves its stakeholders and is maintainable in a way that fits with the project vision. High-level metrics for project success relate to safety, quality, schedule, and budget.The first edition of Recommended Contract Practices for Underground Construction has become a valued resource for the underground industry, serving as a concise guide for drafting and implementation of contract provisions. It provided improvements to underground contracting practices during all project stages. It also presented clear roles and responsibilities for project participants to promote better contracts. This second edition was undertaken by the UCA of SME because the industry has undergone numerous changes over the last decade. Changes in tunneling technology, more common use of design-build as a contracting mechanism, and many lessons learned have sparked some creative contract approaches. The recommendations contained in this edition are intended to guide owners and their engineers in developing and administering contracts and to give contractors a better understanding of the rationale behind contract provisions. The goal is that more underground projects in this country can be best projects, where improved relationships and fair contracts enable all project participants to personally invest in cost-effective, profitable projects, ensuring the continued health of the underground industry.