It is now 20 years since Riga metropolitan project was stopped due to several problems. As the first big infrastructure project – the Southern Bridge – will be finished in few years the next project – the Northern Bridge – has came in spotlight of political discussions. Manville not a single transportation building for public transport is built and visions reach no further than a 800 m tram tunnel under Gaisa bridge. Yes – the vehicles goes under massive replacement program but no improvement in speed is made so far.
The City Development program states at least three possible fast transport systems: light rail (on tram basis), city trains (to split regional service from intra-city service) and train-tram or tram-train service (trains and trams may have common rail sections). How to use these concepts?
Current ambitious port development leaves little hope that existing rail tracks could be used for frequent intra-city service so alternative solution must be found. Here is my concept of gradually increasing speed standards in Vecmīlgrāvis direction. This direction was chosen because Vecmīlgrāvis is a densely populated neighborhood far (9.3km) from the Centre. Now it is served by bus route with suffers from frequent delays.
Tram and railway tracks in Riga have almost the same gauge – 1520mm (trains) 1524mm (trams) - so the rolling stock is interchangeable. Meanwhile heavy rail have higher safety standards so no ordinary streetcars are allowed on train rails. Trams in Riga use 600V DC, but suburban trains 3kV DC – whith according to some unofficial information could be altered to 25 kV AC.
Stage 1 – Expanding the Existing Tram Line No 5
This stage consists of building new heavy rail line (long and high platforms, high centenary voltage and advanced signaling) from Aldaris to Ziemeļblāzma. A 1.9 km tunnel must be built in Vecmīlgrāvis, an additional bridge over Mīlgrāvis and a new pair of tracks in section Mīlgrāvis – Aldaris. Four new stations are proposed – Aldaris, Jaunmīlgrāvis, Vecmīlgrāvis and Ziemeļblāzma. In station Aldaris trains switch to the existing tram line in direction to the centre. Dual power train sets must be used (but not too long to fit in city streets). Station Ziemeļblāzma could become terminal for busses to other neighborhoods (Mangaļi, Vecāķi, Jaunciems, Kalngale). Further North two city train branches are possible – to Vecāķi and Kalngale (where city trains could shared tracks with suburban trains) and to Mangaļi. Ziemeļblāzma city rail line would cut 3 min on evening trip (scheduled) from Central station to Ziemeļblāzma and make public transport much more reliable.
Stage 2 – Tunneling the City
The slowest part in Ziemeļblāzma route is Pētersala – Central station section as it goes through the densely built centre. Two tunneling options are provided – the red one is the straightest, the orange one goes under city districts with poor public transport accessibility. Booth lines would be useful but passengers to Ziemeļblāzma most probably prefer the straightest route (the red one). 3.15 km underground tunnel from Pētersala to Central market (Tirgus) include six stations with connection to street level and rail transport. At station Tirgus trains could continue ride on tram rails to Ķengarags. This tunnel would cut travel times from Central station to Ziemeļblāzma by 10 min.
Stage 3 – Connecting the Two HQ Sections
The missing section from Aldaris to Petersala could be build along existing railways. Station Sarkandaugava is proposed on a new bridge over Tilta street; station Dunte on a new flyover from Vecaķi railway to Krasta freight station. This section altogether will cut travel times to Ziemeļblāzma by 6 min.
The Goal - Reliable and Fast Service
If all stages are realized total travel times in Central station - Ziemļblāzma route will drop from current 39 min by evening bus to 20 min by modern train service with multimodal stations and excellent reliability. If all Tirgus – Ziemeļblāzma section is upgraded to heavy rail standard longer trainsets with single voltage power unit can be used.
The new line will reduce need for suburban train stops within the city so no more then one stop in Saulkrasti direction must be sustained (most probably Sarkandaugava or Vecāķi will stay).