The Port Authority of New York and New Jersey's (PANYNJ) main objective in undertaking the New Jersey Route 495 Exclusive Bus Lane (XBL) Safety Study was to assess the safety impact on traffic operations by permitting 102" wide buses to operate in the XBL. The XBL is a 2.5 mile contra flow bus lane connecting the New Jersey Turnpike and the Lincoln Tunnel. It operates only during the A.M. peak period in the eastbound direction from 6:30 A.M. until approximately 10:00 A.M. The XBL is reserved for vehicles with a capacity of 16 or more (essentially public and private sector commuter buses) During a typical A.M. peak hour, the XBL carries approximately 750 buses in the eastbound direction (1,850 buses during A.M. peak period), each saving 10-25 minutes in travel time. The current operations in the XBL approaching the Lincoln Tunnel in New York were restricted to 96 " wide buses. To conform to the requirements of the Americans with Disabilities Act (ADA) and the convenience offered by the new 102 " wide buses, transit operators expressed a desire to use 102 " wide buses in the XBL. At the outset, it does not appear to be a problem to introduce buses that were only 6 " wider than the previous 96 " wide standard buses. However, the reduction in clearance between the vehicles in the XBL and the adjacent normal traffic flow lane due to the introduction of wider buses in an extremely tight geometric environment on Route 495 was of significant concern to the PANYNJ. The mirror to mirror width of the 102 " wide bus is approximately 120 " (10' 0 ") leaving only 4 " of unoccupied Lane space at some locations along the XBL. The problem is compounded with a sizeable population of commercial vehicles, on coming in the adjacent lanes, accounting for a "shy" factor causing vehicles to veer from each other. To evaluate the safety issues associated with permitting 102 " wide buses, a two phase approach that extended over a year of data collection, analysis and review of the results by an expert panel was adopted. The final recommendations permitted the 102 " wide buses to operate in the XBL subject to the condition that the mix of 102 " wide buses be closely monitored and increase in the mix of 102 " wide buses to 30% of the bus population be immediately followed by further analysis.