OPERATING HOURS Weekdays: 4:45am – 1:20am
Saturday: 5am – 1:20am
Sunday: 5:20am – 12am
FREQUENCY Weekdays – morning: 15 mins / midday: 20 mins / pm peak: 15 mins / evening: 30 mins
Saturday – morning: 30 mins / midday: 20 mins / evening: 30 mins
Sunday – early: 60 mins / morning: 30 mins / midday: 30 mins / early evening: 30 mins / evening: 60 mins

This route is both a east-west and a north-south route servicing the north end of the city from downtown to the Greenhill area near Red Hill Valley. The route operates from 5am to 1am seven days a week.

June 28, 2009 – present
West Main & James With the reconstruction of MacNab Terminal the routing of this route was modified slightly. While the western terminus was technically MacNab Terminal the bus rarely sat there for any length of time. Typically the bus would sit on the shoulder of James St S for its rest period before heading into MacNab. This has remained unchanged, however the routing was modified slightly as well as the stop location. This stop was relocated 25m south on James St S. The bus would turn right onto Hunter as per usual, however instead of then turning right onto MacNab the bus would remain on Hunter and turn right one block later onto Bay St S. The bus would continue on Bay past King St W and return to previous routing.
East Mount Albion Loop
2003 – 2009
West MacNab Transit Terminal Service was added to part of Wellington and Victoria just south of Burlington St E. Eastbound buses would turn right onto Wellington St N, left onto Ferrie St E and then left onto Victoria Ave N. Finally the bus would turn right back onto Burlinton St E and return to the previous routing. Westbound trips would follow the same clockwise loop of the area.
East Mount Albion Loop
2001 – 2003
West MacNab Terminal A slight change was made at Glow Ave. Eastbound trips remained unchanged, however westbound trips no longer turned left on Brampton St, right on Dunn Ave and left onto Glow Ave. Buses would remain on Woodward Ave and turn onto Glow Ave instead. The rest of the route remained unchanged.
East Mount Albion Loop
1995 – 2001
West MacNab Terminal A slight change was made in the downtown with buses using Hunter St W instead of Jackson St W. Buses would now travel south on James St S past Jackson St and turn right onto Hunter St W.
East Mount Albion Loop
1994 – 1995
West MacNab Terminal Two changes were made, one in the middle of the route and one at the eastern end. Buses arriving ot Gage Ave N on Burlington St would now turn right onto Gage, left onto Beach Rd, left on Depew St and then right back onto Burlington St E. Westbound buses travelling on Industrial Dr would make a left on Depew, right on Beach, right onto Gage and then left back onto Industrial Dr. Additionally the eastern loop point was extended with buses travelling south on Quigley Rd no longer turning onto Veevers but instead passing this turn and turning right onto Greenhill Ave. The bus would then turn left on Mount Albion Rd and terminate at the Mount Albion Loop. Buses travelling back would leave the loop travelling north on Mount Albion, turn right on Greenhill Ave, left on Quigley and then continue the rest of the route as previous.
East Mount Albion Loop
1991 – 1994
West MacNab Terminal The 4A branch was eliminated by re-routing ‘Route 53 Burlington’ from Kenilworth Ave to Ottawa St and making the 4A branch the main line. Additionally ‘Route 57 Nash’ was eliminated and the route was extended to service that area. When the eastbound bus reached Woodward & Barton the bus would now turn left onto Barton St E followed by a right onto Nash Rd N. The bus would then travel southbound on Nash Rd and turn right onto King St E. Next the bus would turn left onto Quigley Rd, left on Veevers, right on Ambrose and a right on Greenhill Ave to arrive at the loop. The return trip would turn right on Quigley, right on King, left on Nash, left on Barton, right on Woodward, left on Brampton St, right on Dunn Ave and left onto Glow Ave. The remainder of the previous routing remained unchanged.
East Quigley & Greenhill
1989 – 1991
West MacNab Terminal Heading westbound the 4A branch would travel north on Talbot, turn left onto Barton St E, right on Woodward Ave, left on Glow Ave, right on Parkdale Ave N followed by a left onto Burlinton St E. The bus would merge onto Industrial Dr and meet the main line at Gage coming back from the Kenilworth Traffic Circle. The main branch returned via Kenilworth, right on Lawrence, right on Huxley, left on King, right on Ottawa, left at Beach, right on Gage and left on Industrial Dr. The bus would continue west onto Burlington St E until reaching James St N where the bus would turn left. The bus would then travel through downtown on James St and turn left onto Jackson St W, followed by another left at MacNab St S. The bus would cross Main St W to arrive at the MacNab Terminal.
East - Kenilworth Traffic Circle
– Melvin & Osborne (4A)
The bus would leave the loop at the MacNab Terminal and turn left onto King St W, followed by a right on Bay St N. Next the bus would turn right onto York Blvd and then left back onto MacNab St. The bus would travel north on MacNab St N until reaching Murray St where it would turn right followed by a quick left onto James St N. The bus would then turn right onto Burlington St E. Arriving at Gage Av N the bus would branch off. The main route would turn right onto Gage St N and then left onto Beach Rd. The bus would next turn right on Ottawa St N, left onto King St E and then right onto Kenilworth Ave S, arriving at the loop point at the Kenilworth Traffic Circle. The 4A branch would continue eastbound on Burlington St E past Gage until arriving at Parkdale Ave N where it would turn right. The bus would then turn left onto Glow Ave, right on Woodward Ave, left on Melvin to arrive at the loop point at Melvin & Osbourne.

This photo was taken September 26, 2007 of HSR 9916 running as a Route 4 Bayfront on James St S in Downtown Hamilton.

This photo was taken July 2, 2007 of HSR 0709 running as a Route 4 Bayfront at the MacNab Terminal.