Interchange types include diamond, parclo, single-point urban (SPUI), and system interchanges. NJDOT requires an Interchange Justification Report (IJR) or Interchange Modification Report (IMR) per FHWA policy for all new or modified interchanges on the Interstate system. Minimum ramp design speed is typically 70% of the mainline design speed. Acceleration and deceleration lane lengths per AASHTO Green Book Table 10-3 and 10-4.
References: AASHTO current edition, NJ Standard Specifications, FHWA Technical Advisories, and applicable federal regulations (23 CFR). Contractors shall maintain current copies of all referenced standards on the project site.
Source: NJDOT Highway Design Manual, 2024 Edition. Pages 19–20 of 37.