4 + 0 traffic routing
In road construction, 4 + 0 traffic routing is understood to be a construction-related transfer of directional traffic from two to one directional lane in the area of a job . The prerequisite for this is a suitable cross-section of the road that is both sufficiently wide and adequately paved.
By using the 4 + 0 traffic routing, one directional lane becomes traffic-free, so that construction work can be carried out there with almost no disruption. The method thus represents an alternative to building under the rolling wheel . On the other lane, the traffic flows are separated from one another and guided by means of construction site markings , marking buttons and passive protective devices .
Due to this traffic routing, one-way traffic has a limited lane width. Therefore, a speed limit and an overtaking ban for trucks are imposed there. The left-hand lane is usually only so wide that it can only be used by cars and motorcycles. In order to avoid accidents in the future, signs are being set up as an experiment that encourage people to move from one place to another.
Despite numerous safety measures, traffic accidents often occur in such sections . In addition to the limited space, the reasons for this are often excessive driving speeds and unclear traffic management. The latter applies particularly at the beginning and at the end of the assignment (so-called transfer or return).
Particularly critical situations can arise in the event of a vehicle breakdown when using the hard shoulder (4s + 0 traffic routing), as the broken-down vehicle cannot be removed from the lane immediately and the following traffic is significantly hindered.
The guidelines for the construction of road cross-sections result in a lane width of 11.50 m for two-lane motorways with two lanes plus hard shoulder. The lanes each have a width of 3.75 m, the hard shoulder 2.50 m plus marked edge strips of at least 0.50 m (or 0.75 m). In a 4-0 system, this RQ 29 (or RQ 29.5) is redistributed into 3.00 m (or 3.25 m) for the truck lanes and 2.50 m for the car lanes 0.15 m to 0.25 m wide strips for the markings.
Norms and standards
Germany
Austria
- RVS 05.05.40 ff. - Construction site protection
Switzerland
- SN 640 885c - Signalization of construction sites on motorways and motorways