REMOVAL OF THE A1-A400 ARCHWAY GYRATORY IN TFL ROADS TASK FORCE PROGRAMME
By John MacBryde
The Archway Gyratory is one of the 30-odd (very odd) gyratories which have been identified in the Transport for London (TfL) programme for examination and possible early removal. “The Roads Task Force, a key election pledge by the Mayor, is looking at how TfL and the boroughs could redesign gyratories…and continue to make roads safer for all users. It is also looking at how the road network could better serve local communities.” [GLA Press Release]
This “squareabout” junction was conceived by the London County Council in 1963 as part of the Archway Tower redevelopment scheme. It was intended to create the southern end of the then projected A1(T) dualling as far north as the A1-A1000 Wellington Junction, the northern part being the responsibility of the Middlesex CC, beyond the historic Archway Bridge. Only the short 6-lane widening was carried out by the LCC in 1963-64. The northern (1500 m) section was left as a 9 m single carriageway since MCC and the MoT were unable to agree a detailed scheme or finance.
Enter the late Transport Minister Marples. Being aggrieved by his recent M1 motorway ending up at the end of an unimproved A1(T) road in North London, he launched one of his more “juicy” one-way schemes of the 1960s. This created a de facto dual carriageway through Highgate by twinning the existing A1 road with the relatively minor B519 up Highgate and North Hill. Cue outrage by the wealthy burghers of Highgate Village who (largely) stopped it all happening.
The great irony, clearly lost on Marples, was that the Archway Road was conceived in 1820 as a bypass to Highgate Hill ! Marples megalomania required several satellite one-way systems to the north, south, east and west of the diamond shape mega-scheme in the middle. The damaging Highgate Village one-way lasted from 1963-93, ie until the formal DETR abandonment of the A1 dualling.
This dualling was the subject of two near-riotous public inquiries in the 1970s. Only two of the satellite gyratories, ie the Wellington A1-A1000 intersection to the north-west and the Archway A1-A400 junction to the south-east, survive to the present time. The latter is the subject of investigation by TfL for possible abandonment (as is also the Wellington Gyratory). A possible solution, prepared by the London Group of the Campaign for Better Transport (CBT) and basically derived from an earlier scheme of the local Better Archway Forum (BAF) is shown on the diagram (right).
Key to Diagram:
Outbound Traffic Lanes shown in WHITE
Inbound Traffic Lanes shown in BLACK
Kerbside [24h] Bus Lanes shown in RED
This effectively exploits the 3-4 lane capacity of the legs of the “squareabout” by reverting two of them (NE & SE) to two-way general traffic and two of them (NW & SW) to predominantly bus-priority “transit malls” (to use the US terminology) with limited [20 mph] access and egress for B519 traffic up and down Highgate Hill. The carriageway space outside Highgate Underground could thus serve as unified boarding and interchange area for the several LT bus routes passing through or terminating at Archway. This would be consistent with its old  GLDP status as “A Major Interchange”
The main objection to the revised scheme, as traffic engineers will be very quick to point out, is that there is “negative reserve capacity” compared with current peak hour flows. In other words, the same number of vehicles cannot negotiate the new layout. However, if throughput is calculated in terms of persons per hour (pers/h) as opposed to vehicles per hour (veh/h) there will probably be rough equivalence or even surplus capacity, given very much higher bus occupancy. Moreover, it would be eminently possible to speed bus movements by dint of virtually continuous kerbside bus lanes which would also act as de facto safer cycle lanes through the currently hazardous gyratory layout; two of the key issues and objectives set out in the 2012 Roads Task Force Report and its Proposals
The various arms of the former gyratory would thus conform to four of the nine individual categories of street (as defined in the 3×3 (“Tool Box”) matrix in the Roads Task Force Report). These might be characterised as follows (in all cases they should be subject to the current local (Islington) 20 mph speed limit).
|NE: Archway Road||Directional lane management?||B3 CITY STREET|
|SE: St Johns Way||Asymmetrical 3-lane layout||C1 LOCAL STREET|
|SW: Highgate Hill||Interchange + raised surface?||C2 TOWN SQUARE|
|NW:Tollhouse Way||Asymmetrical incl 2 bus lanes||C3 CITY PLACE|
© 2014 John MacBryde DA(Edin) DipTP(UCL) ARIBA MRTPI MCILT