I-10 Broadway Curve Draft Environmental Assessment I-10 Broadway Curve Draft Environmental Assessment Page Intentionally Left Blank I-10 Broadway Curve Draft Environmental Assessment Page Intentionally Left Blank I-10 Broadway Curve Draft Environmental Assessment Contents Contents ENVIRONMENTAL COMMITMENTS ................................................................................. MM-1 MITIGATION MEASURES ................................................................................................. MM-1 I. INTRODUCTION .............................................................................................................. 1 I.A. Explanation of an Environmental Assessment .......................................................................1 I.B. Location ...............................................................................................................................1 I.C. Project Background and Overview ........................................................................................3 II. PURPOSE AND NEED ...................................................................................................... 6 II.A. Introduction .........................................................................................................................6 II.B. Project Purpose ....................................................................................................................6 II.C. Project Needs .......................................................................................................................6 II.C.1. Need Based on Regional Mobility and Access ....................................................................................... 7 II.C.2. Need Based on Traffic Operations ...................................................................................................... 10 II.C.3. Need Based on System Linkages ......................................................................................................... 13 II.C.4. Summary ............................................................................................................................................. 13 II.D. Conformance with Regulations, Land Use Plans, and Other Plans ........................................ 15 III. ALTERNATIVES ANALYSIS ............................................................................................. 16 III.A. Prior Studies and Alternatives ............................................................................................. 16 III.A.1. Interstate 10 Corridor Study................................................................................................................ 16 III.A.2. I-10 Corridor Improvement Study ....................................................................................................... 18 III.A.3. Spine Corridor Study ........................................................................................................................... 20 III.A.4. I-10 Near Term Improvements ............................................................................................................ 21 III.B. Alternatives Considered ..................................................................................................... 22 III.B.1. Public and Agency Scoping .................................................................................................................. 22 III.B.2. Preferred Alternative .......................................................................................................................... 23 III.B.3. No-Build Alternative ............................................................................................................................ 24 IV. AFFECTED ENVIRONMENT ............................................................................................ 31 IV.A. Environmental Issues Eliminated from Detailed Study ......................................................... 31 IV.B. Land Ownership, Jurisdiction, and Land Use ........................................................................ 32 IV.B.1. Existing Conditions .............................................................................................................................. 32 IV.B.2. Environmental Consequences ............................................................................................................. 34 IV.B.3. Environmental Commitments and/or Mitigation Measures ............................................................... 36 IV.B.4. Conclusion ........................................................................................................................................... 36 IV.C. Socioeconomic Considerations ............................................................................................ 37 IV.C.1. Existing Conditions .............................................................................................................................. 37 IV.C.2. Environmental Consequences ............................................................................................................. 40 IV.C.3. Environmental Commitments and/or Mitigation Measures ............................................................... 43 IV.C.4. Conclusion ........................................................................................................................................... 43 IV.D. Title VI and Environmental Justice ...................................................................................... 44 IV.D.1. Existing Conditions .............................................................................................................................. 44 IV.D.2. Environmental Consequences ............................................................................................................. 58 IV.D.3. Environmental Commitments and/or Mitigation Measures ............................................................... 59 IV.D.4. Conclusion ........................................................................................................................................... 59 IV.E. Cultural Resources .............................................................................................................. 60 i October 2019 NH-010-C(220)T 010 MA 149 F0072 01C I-10 Broadway Curve Draft Environmental Assessment Contents IV.E.1. Existing Conditions .............................................................................................................................. 61 IV.E.2. Agency Coordination ........................................................................................................................... 66 IV.E.3. Environmental Consequences ............................................................................................................. 67 IV.E.4. Environmental Commitments and/or Mitigation Measures ............................................................... 68 IV.E.5. Conclusion ........................................................................................................................................... 68 IV.F. Section 4(f) Resources ........................................................................................................ 69 IV.F.1. Regulatory Context .............................................................................................................................. 69 IV.F.2. Coordination and Consultation ........................................................................................................... 71 IV.F.3. Existing Conditions .............................................................................................................................. 71 IV.F.4. Environmental Consequences ............................................................................................................. 76 IV.F.5. Environmental Commitments and/or Mitigation Measures ............................................................... 83 IV.F.6. Conclusion ........................................................................................................................................... 83 IV.G. Traffic and Transportation .................................................................................................. 84 IV.G.1. Traffic Volumes.................................................................................................................................... 84 IV.G.2. Operations Analysis ............................................................................................................................. 85 IV.G.3. Traffic Impacts During Construction.................................................................................................... 87 IV.G.4. Environmental Commitments and/or Mitigation Measures ............................................................... 87 IV.G.5. Conclusion ........................................................................................................................................... 87 IV.H. Air Quality .......................................................................................................................... 88 IV.H.1. Mobile Source Air Toxics ..................................................................................................................... 88 IV.H.2. Greenhouse Gases ............................................................................................................................... 90 IV.H.3. Existing Conditions .............................................................................................................................