third of the trains to the main station on Saturdays, only a few were previously connected. in the FVV the route bore the line letter N. Dreieich Railway or Dreieichbahn (61): (Frankfurt central station -) Dreieich-Buchschlag - Rödermark-Ober-Roden (- Dieburg)The operated by the DB Regio Dreieichbahn was referred to in the network of Frankfurt traffic network as S-Bahn line 11. The Dreieichbahn has been running every hour since summer 2016 to the main station. On other lines such as the Horlofftalbahn (48, HLB) or the Odenwaldbahn (82/85, Vias) also in the rush hour additional trains to and from Frankfurt Hauptbahnhof; but they have a weaker clock density. While now all services are also provided on the aforementioned lines of railcars, drive only individual pairs of trains on the line 34 at rush hour and because of the operational link in Bad Vilbel two of the three bound train pairs on the line 48 as a wagon train with double-decker and a locomotive Class 245. Problems and accidents Punctuality The biggest problem experienced on the Rhine-Main S-Bahn is frequent unpunctuality, one reason for which is the shortage of capacity in the Citytunnel. Capacity of the tunnel was increased from 22 trains per hour (in each direction) to 24 trains per hour in 2010 by optimising the Punktförmige Zugbeeinflussung signalling system, rather than upgrading the system to the more modern Linienzugbeeinflussung (LZB) system, as used on the Munich S-Bahn to achieve a throughput of 30 trains per hour in each direction in the Munich core city tunnel. A further cause of delays is that many of the S-Bahn lines share track with freight trains, regional trains and inter-city trains. Longer distance passenger trains take priority over the S-Bahn, which frequently has to stand for up to 10 minutes to allow the other service to overtake. Mixed services are particularly found along the S6, S7, S8 and S9 routes. The operators recognise the need to separate S-Bahn services from other services along these routes. The first stage towards this was originally scheduled to start in 2007, doubling the number of tracks from two to four on the S6 line between Westbahnhof and Bad Vilbel, but in October 2011 Deutsche Bahn stated that it expected work to start in 2014 and the extra tracks to go into service in 2018. Rolling stock 165 S-Bahn trains are in operation. On December 31, 2012, the breakdown