Effektiva omkörningsfält på 2+1-vägar: trafiksimuleringar av olika utformningsalternativ ur ett framkomlighetsperspektiv


The traffic performance at oncoming lane separated highways with alternating dedicated overtaking lanes (so called 2+1 roads), is dependent on the share of two lane segments (also known as the share of overtaking length). In order to maximize utilization and traffic performance, the configuration of the overtaking lanes should be designed to avoid congestion and delays. Short overtaking lanes implies limited time of queue discharge, but gives frequently recurring possibilities to overtake. Increased lengths of overtaking lanes imply the possibility to overtake several vehicles per overtaking lane, but increases the risk of catching up slower vehicles since the configuration also results in increased lengths of one lane segments.

This report presents a traffic simulation study of how different configurations affects the throughput at 2+1 roads. The results indicate that overtaking lanes between 1 050 and 1 400 meters result in shortest travel time. However, the differences are small (~0.4 seconds/km) and not statistically significant. Thus, the benefit of optimizing the configuration in terms of throughput could be questioned. Based on the results, it becomes reasonable to question the concept of designing 2+1 roads with long overtaking lengths (which corresponds to the recommendations from the Swedish Transport Administration (Trafikverket)). The major risk of catching up a slower vehicle at the one lane segments obviously affects the travel time.



ERPUG 2017

The five year anniversary of  European Road Profile Users' Group (ERPUG) Forum will take place at Ramboll head quarter, Copenhagen, Denmark October 19-20, 2017. 

Shipping and the environment – research meets reality

Centre for Transport Studies (CTS) in co-operation with Ports of Stockholm invite you to the seminar Shipping and the environment – research meets reality.




The five-year anniversary of European Road Profile Users' Group (ERPUG) Forum will take place at Ramboll head quarter, Copenhagen, Denmark October 19-20, 2017.


Self-driving buses in Sweden next year?

A self-driving, fossil-free bus. This idea might become reality through a forthcoming collaborative project involving the Swedish National Road and Transport Research Institute (VTI), Linköping University and several other participants. The project group aim...


New climate-proof solutions for hard surfaces in cities

High-density road infrastructure that emphasise maximum durability and minimum maintenance create inflexible systems, which put increased stress on urban trees and lead to increased risk for flooding. Over the past five years, the ‘Climate-proof solutions for...


VTI is preparing for automated vehicles

Automation of traffic systems will lead to major changes. The European Union’s (EU) CoEXist research project began in June 2017 with the aim of preparing cities and road operators for the introduction of self-driving vehicles. The Swedish National Road and...


Vehicle Driver Monitoring: sleepiness and cognitive load

To prevent road crashes it is important to understand driver related contributing factors, which have been suggested to be the critical reason in 94 per cent of crashes. The overall aim of the project Vehicle Driver Monitoring has been to advance the...


Tomas Svensson new director-general

Tomas Svensson was today appointed Director-General of VTI. Tomas has been acting Director-General since January 2017.