The northern section of the junction consists of ramps joining the M8 with the A804, plus a link between the motorway and the city centre, to the east.

An entry from the A804 leads on to the northbound M8, passing under the northbound J18 exits, before climbing to join the motorway beyond. 

The J18 exit ramp splits, one half descending to the A804 and the other climbing and curving eastwards towards the city centre.  Traffic which joined at J20 must exit here, with a choice of routes.  The only exit from the mainline becomes the right hand lane climbing out to the city centre.

The 'bridge to nowhere' crosses over the top.

Notice the matrix sign with flashing yellow lights and a 40 advisory speed limit.

The lights are signed out of use - and were being worked on by a Siemens engineer.   Large "Crossing closed" signs are blocking pedestrians' access to the crossing - but don't appear to make much difference! 

The metal footbridge from which the photo was taken is a considerable detour, and has awkward stepped ramps.  (The southbound A804 has to be crossed on the level anyway.)

Although it's still only motorway traffic at this point, the signposting is black-on-white with blue borders, for local directions only.

The black on yellow signs are diversions used during works on the motorway.  In this case, the diversion is a semi-permanant division between mainline traffic and traffic joining at junction 20.  The joining traffic is forced to leave at junction 19 and here at junction 18.  Traffic wishing to continue on the motorway must divert via the A804 at Charing Cross and then rejoin.

The 'keep right' sign is actually on the gore, and must be ignored by all traffic on the  Anderston branch.

The orange box is a standard motorway emergency telephone.

The double exit ramp is on the left, and the main carriageways on the right, with traffic from the A804 climbing up between them to join the motorway. 

The single pillar in the middle is for the 'bridge to nowhere'.

The ground rises very steeply just beyond the Abbey National building, and the ramp meets surface level without descending.

Here, looking south along the A804 towards J19, with the motorway climbing out on the right, two slip roads, each marked with one lane, climb up to join it, with the ramp from the eastbound A814 crossing from right to left.  The two-lane motorway thus gains three additional lanes before the Kingston bridge.

Two other ramps descend to the lights under the junction, one, on the left, on the southbound A804, and one, in the middle, from the southbound motorway 

The end of one of a gantry sign for the J19 exit can be seen to the right of the photo

There are only two through lanes beyond J19, but the Fire Engine has no hesitation in using the auxiliary lane to get past slower traffic.

(See it jammed in traffic in the next photo!)