It's only a short stretch, running the length of I-495, but the XBL in the Lincoln Tunnel is a huge reason why people bother with the bus in northern NJ.

When I was commuting by bus, the inbound morning trip (with XBL) was 20-30 minutes, and the outbound evening trip (without XBL) was 30-45 minutes.

https://www.panynj.gov/bridges-tunnels/en/lincoln-tunnel/xbl...