VAST CHANGES PLANNED

Chronicle (Levin), 2 September 1946, Page 4

VAST CHANGES PLANNED

Marn Road To Wellington FOUR LANE WAY STARTED A start has been made, without gain ing more than casual remark from those who have notieed eu'lvert eoflstruction And preliminary earthworks north or Johnsonville, upon a main north motor!way which will improve access to Wellington as greatly as -have the transformatioh of Ngahanranga Gorge aua the replaeing of the one-time iong drag over Paekakariki Hill by the level going of the coastal road from Pukerua .onwards. But for the war the realignment or ithe main road from Johnsonville to Tawa Flat would already have been accomplished, but perhaps it is weii that there has been delay ifl cominencoment of the work, for the plan now deeided upon looks eonsiderably further iahead than did the pre-war plan. ; The Johnsonville-Tawa Flat lengtn will be the first length of a four-lane motorway, with a central barrier dividing north and sou'th lanes, which wiu :be carried on to Paraparaumu in its first stage, and later, further north. A principie that has been accepted as : virtually essential in main highway construction overseas, but which will be ,new to New Zealand. It will be a* "limited aecess" highway,- specifieal'iy designed for through traffic.

There will be no grade intersections, And there will be few points at whicn traffic may enter or leave the througn lanes, and then by " clover-leaveS' The highway will avoid townships and ■settlements for the safety of everyone eoncerned, and ribbon development — the eurse of new highway construetion, in that it re-introduces the eompbeatio'ns of traffic conflict particularly to be avoided — is to be diseouraged, as it is, to the point of prohibition, along railway routes. Local and stock trattic will eontinue on the present main and seeondary roads, which wiil also carry traffic bound to further destinations nntil one of the well-spaeed points ot access to the through traffic route is reached. Old Roads Beyond Remedy. Present and anticipated traffic volume in New Zealand are considered jusf.ification for this further advanee in highway construetion on the more heavily trafficked sections about main centres, and there are, for the Wellington area, particular reasons for departing from old alignments. The twisting, hose-and-cart era length between Johnsonville and Tawa Flat is patently too bad a job of road building to be remedied; further north, from Paekakariki towards Paraparaumu, road ehgineers have tried for 50 years elmore to make a job of a main road binir, on'a bad swamp foundation, and have never suceeeded in achieving Imtter than seeondary road standard.

The First Section. By one or another of the alternati-ve means still under discussion, traffic to and from the gorge will be talcen through Johnsonville without traversing local and shopping traffic, and local and Khandallah- Johnsonville traffic will join in before the new highway sweeps to the east of the present tortuous road. It has generally been assumed tuai; the new highway will follow the old railway reservation, but this wiil not be so, except in general fashion, for the old railway was built when ridges and gullies, which are not of much account now ithat heavy ^arth-shifting plant is available, were too eostly to taekle with the pick and shovel. Consequently, the old railway reservation, though much straxghter than the old road, does not conii>ly in any satisractory degree as regards visibility on curves with modern highway standards. Apart from three bends, upon very wide radius, the motorway will strike a generall}- direct line from Johnsonville to Tawa Flat, with a maximum grade of 1 in 25, and that over a short d-is-tance only. For modern plant the cpirntry preseiifdy-n-b difficulties. ^ There wi|l:-'-be liiAAyiyicuts; aiid. .fflls, of Apursp, bnfc there"v'3^i^ifjg . heav-y ..rock>i^Mf$al|/hAiLto;- b^.,/d§fe in reinaking -tA'e heavier cuts along the coastal highway from Plimmerton to Paekakariki. Beyond Tawa Flat, the highway will sweep west, crossing the present road and railway by overbridge, and wiil ■ pass beliind the Porirua Hospital to the soutliern sliore of the Porirua inlet, and on across the mudflats (to be reclaimed as part of the Porirua-Titahi Bay housing and indifetrial development) to tlie westem sliore of the inlet. It will run along this sliore to a point approximately opposite the military camp on the Dolly Varden peninsula, and will eross the harbour channel by a new bridge, a little longer than the Paremata traflie bridge. Great Changes For Dolly Varden As the Porirua-Titahi Bay-Paremata-i Plimmerton development grows, the sandy point of the Dolly Varden settiement, on which an old-time stone military barraelcs once stood, and where, for the' last war, woodeit stores and huts were rushed up, will become an important traffic junction, for the general picture is that there will be laid out an extensive railway yard, as the ju-netion between the Main Trunk and the pro-jec-ted railway from the Hutt Vailey, via Haywards Hill, but that is further in the future than the motorway. Across the new traffic bridge, the motorway will join the coastal highway just -north of Plimmerton station, by overbridge at the railway and with a "clover-leaf " for the joining in of Plimmerton, Paremata, and Pahautanui traffic. , ■ At Paekakariki the motorway will cross the railway by overbridge and "clover-leaf", and will run nearer the sea through the sandhill eountry, avoiddng the swamp lands that have been a continuing headache for highway engineers, and will reacli Paraparaumu a few chains east of the aevodrome. The general line of route is laid out beyond Paraparaumu, but those stages are out- • Side the picture of regional development; of the next ten> years as accepted at present.