Kenniscentrum voor fietsbeleid
  • 1. Bypass and spiral markings on multi-lane roundabout

    Maastricht, Tongerseplein, multi-lane roundabout. Tongerseplein is a busy multi-lane roundabout near the Maastricht town centre. It had a reputation as the most dangerous location in the entire province of Limburg. A large number of measures by local authorities have improved cyclists' safety. Among these: spiral markings, a bypass and reducing the number of lanes on an exit.

     

     

  • 2. Location en intensitities.

    With over 40,000 mv/24h Tongerseplein is an extremely busy roundabout. The majority of vehicles move from south to west and vice versa. This is the N279, connecting the A2 to the Belgian border. At the southern leg, Prins Bissschopsingel, intensities are highest (30,000 mv/24h). This road has a clear arterial character. Daily over 7,000 cyclists use Tongerseplein.

  • 3. Old situation

    Until 15 years ago this was an old-fashioned roundabout with right of way for traffic from the right. It was a tricky situation for cyclists. They had to use service roads and had to yield to all motor vehicles entering and leaving the roundabout. As a result of easy curves, double lanes and the priority regime the speed of motor vehicles was relatively high. Particularly on the southern leg drivers would leave the roundabout at high speeds (average 46 km/h, 20% exceeding 50 km/h). Yet there were few bicycle accidents.

  • 4. Priority for cars

    Gradually the priority regime of the roundabout was changed. In 1991 signs and markings regulated priority in favour of motor vehicles on the roundabout. The lay-out of the roundabout was not adapted at the time. Little change, too, for cyclists: on service roads and no priority. The number of bicycle accidents remained relatively low. Yet during observations conflicts on the exits were spotted, that might have lead to serious injuries if traffic participants had not taken action at the last moment.

  • 5. Priority for cyclists

    After extensive conversions in 1995 cyclists, too, received right of way on the roundabout. To a large extent the changes are in accordance with the current CROW recommendations for two-lane roundabouts (see diagram). A circular bike path was located at approx. 5 metres’ distance from the lane. The curves on entering and leaving the roundabout were tightened. The entrances remained two lanes, but the exits were reduced to a single lane only. Only the busy south exit kept its two lanes. A platform was constructed for the bicycle crossing. These changes were not a success as far as safety was concerned. In 3 years 13 accidents with injuries occurred.

  • 6. Series of measures

    In 2002 local authorities have implemented a series of measures in order to increase safety on the roundabout. Spiral markings have been used and the number of lanes on the south exit has been reduced, in combination with a bypass. At the entrances the curvature radius has been tightened as well. The various measures are depicted in the following photos.

  • 7. Spiral markings

    Until the latest reconstruction the roundabout had two lanes, but most exits were single-lane only. One of the disadvantages was that motorists on the inner lane of the roundabout had to change lanes in order to leave the roundabout. A rather complicated manoeuvre requiring all concentration. This increases chances of motorists overlooking cyclists. Thanks to the spiral markings motorists no longer need to change lanes.

  • 8. Single lane exit

    The two-lane exit on the south leg has been reduced to a single lane. There prevents the occurrence of any blocked-view accidents. These accidents occur when the view of motorists in the inner lane is obstructed by lorries or cars in the outer lane. And vice versa: when cyclists can not see a car in the second lane because of a lorry or car in the first lane. Another disadvantage of a two-lane exit is that drivers may cut corners by using both lanes when traffic is slow. This increases speeds.

  • 9. Bypass

    However, the disappearance of a lane on the south leg has reduced the roundabout’s capacity. By way of compensation a bypass has been constructed for the major west to south flow of cars. Cyclists cross this bypass at right angles. The curves for the cyclists are quite tight (R=approx. 2 m= approx. 7 km/h), probably due to lack of room. In order to increase safety and car circulation local authorities have decided cyclists should yield to motorists on the bypass.

  • 10. Detector loops

    Detector loops have been installed on the approaches. These ascertain whether waiting times for car traffic become too long. In that case the traffic lights in the vicinity of Tongerseplein will stockpile traffic heading for the roundabout.

  • 11. Priority for cyclists

    On the entrances and exits of the roundabout the cyclists have retained their priority. Since the measures have been implemented, hardly any accidents have occurred. In particular have there been hardly any conflicts between cars and bicycles.

Gerben Siebenga (Gemeente Nijmegen)
18-09-2007 @ 16:04

In principe een goede zaak, het ombouwen van een verkeersplein bibeko naar een rotonde met fietsers in de voorrang. Voor de verkeersveiligheid van fietsers een hele voorruitgang.

Er wordt echter niet ingegaan op de doorstroming van het autoverkeer in de nieuwe situatie. Niet alleen de intensiteiten zijn aanzienlijk, maar feitelijk wordt de capaciteit van de rotonde minder vanwege enkele op- en afritten. Bovendien moeten auto's voorrang verlenen aan fietsers, wat ook ten koste gaat van de capaciteit. Het zou mooi zijn als er met een nameting/berekening kan worden aangetoond dat de doorstroming nog altijd voldoende is in deze situatie.

Gerben Siebenga, Grontmij

Hans Voerknecht (CE)
26-06-2008 @ 01:35

Translation: Gerben Siebenga (Grontmij Nederland B.V.)

18-09-2007 @ 16.04

It is basically excellent to transform a roundabout in town into a roundabout with priority for cyclists. Quite an improvement in road safety for cyclists. However, the circulation of motor vehicles in the new circulation is not discussed. Not only are the intensities considerable, but due to several approaches and exits the roundabout’s handling capacity is reduced. Additionally motorists have to yield to cyclists, further compromising capacity. It would be nice if additional measurements/calculations could prove circulation is still; sufficient in this situation. Gerben Siebenga, Grontmij

Richard Severijns (Groen)
20-05-2011 @ 23:10

Deze rotonde ken ik zeer goed omdat ik zelf in Maastricht gewoond heb. Ik heb de oude situatie gekend toen ik er zelf nog woonde en wordt nu bij bezoek aan mijn familie geconfronteerd met de nieuwe situatie.

De bypas van de Tongerseweg naar de Prins Bisschopsingel is voor de doorstroming van het autoverkeer een goede zaak. Voor de fietsers iets minder omdat die bij de oversteek over de bypass niet in de voorrang zitten. Zoals op foto 6 en 9 te zien is, moeten de fietsers de auto's op de bypass voorrang verlenen. Dit leverde in het begin soms bijna kop-staartbotsingen op met Belgische auto's omdat deze de fietsers op de bypass voorrang verleenden.

In België worden op rotondes ook vaak bypasses aangelegd om rechtsaflaand verkeer om de rotonde heen te leiden. Maar in tegenstelling tot de bypass in Maastricht moeten in België de automobilsten voorrang verlenen aan de fietsers die de bypass willen oversteken. De fietsers worden consequent in de voorrang gehouden, ook op de oversteek over de bypass. Belgische automobilisten stopten in Maastricht dus ook voor de fietsers die de bypass wilden oversteken met het gevolg dat dit niet door de Nederlanders verwacht werd.

Mij lijkt het logischer om de fietses op de bypass ook in de voorrang te houden zoals bij alle overige fietsoversteken op de rotonde. Op die manier kies je duidelijk vóór de fietser en geef je aan deze prioriteit te geven boven het autoverkeer. Tegelijkertijd wordt de snelheid van het autoverkeer op de bypass vertraagd omdat automobilisten extra rekening moeten houden met overstekende fietsers. Op Belgische rotondes wordt de verlaging van de snelheid op de bypass nog eens extra afgedwongen door de oversteek van de fietserd op een drempel te leggen.

Maar omdat het voor een automobilist tot op het laatste moment onduidelijk is of de fietser zijn weg vervolgt langs de bypas of op de rotonde dan wel de bypass wil oversteken, kan ik ook wel begrijpen dat om de fietser tegen zichtzelf te beschermen de fietser voorrang moet verlenen zodat de fietsers zich niet voor de auto's 'smijten' omdat ze voorrang hebben.

Richard Severijns
Fietsersbond, afdeling Pajottenland (www.fietsersbond.be/pajottenland)

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