Rewarding motorists for avoiding rush hour

Summary

The accessibility of Utrecht is strained by construction work. To address this, Utrecht made a package of measures, one of which a pilot-project that rewards motorists who avoid morning rush hour.

Implementing sustainable mobility

Since 2007 extensive infrastructural adaptations were implemented in the "Utrecht-West" area. One of the consequences of this large-scale restructuration is a temporarily decrease of traffic capacity on some main roads and highway junctions. Aware of these traffic disturbances, the city of Utrecht, in close coordination with the national highways authorities, founded a public-private cooperation between five organisations – called ‘Stichting Utrecht Bereikbaar' (SUB) – which has one objective to limit the negative impacts on the traffic flows due to road works in and around Utrecht.
The SUB has implemented several measures to prevent traffic disturbances in a short time frame and encourage changes citizens’ behaviours towards sustainable mobility options. In this context, the MIMOSA measure ‘Rewarding mobilists for avoiding rush hour’ was designed to reach the combined objectives of the national initiative and of the local public-private cooperation. The specific objective of the measure was to reduce the amount of private cars in Utrecht-West area during the morning rush hours (6 am – 10 am) by giving financial incentives to car drivers who chose another itinerary, use another transport mode, or drive before or after the morning peak hours. Therefore a pilot-project was implemented and focused on road sections strategically selected along the national highway A2 and along five main roads in the southern and western part of Utrecht.

The principle of the pilot project consisted in identifying car owners who usually drive along the selected roads in the morning rush hours and in rewarding them with €4,- if they did not drive along these roads at that time of the day during the pilot. Preliminary studies showed that a reduction of 1,000 cars along the selected roads would be sufficient to prevent increases in the length and duration of traffic congestion in the morning rush hours. Consequently, the expected objective of the pilot project was to reach a participation rate of at least 1,000 car drivers per day.

Progress

In order to draw a baseline for the pilot-project and for the impact evaluation, the contractor placed cameras on the selected locations. The license plates of the ones who were identified more than three times within two weeks were selected. From the 15,555 people that were selected and invited by letter to participate, 4,026 car owners decided to participate

The pilot project was applied during a period of 13 weeks. For each of the 4,026 cars participating, the frequency of use per week of the all main roads leading to the city in the morning rush hours was measured. To do so, a second subcontractor placed surveillance camera system along other strategic main traffic axes to make sure that the participants did not drive along these axes and increase the traffic flow in this other part of Utrecht during the morning rush hours. The comparison between the number of trips registered during the pilot project period and the number registered during the first stage of the measure enabled to determine which cars owners contributed effectively to the measure and should therefore be rewarded.

Within this pilot a participant was rewarded with € 4 when he avoided these roads during the morning rush hours on working days between 6 AM and 10 AM. Experiences with rewards in another pilot in the Netherlands were used to determine this amount, and naturally the available budget relating to the desired number of avoided trips in the rush hours also determined this amount.

In the autumn of 2010 it became clear that a second pilot could be executed in relation to the road works planned in the beginning of 2011 at highway A2 and one of the main intersections close to the centre. To establish behavioural change, a pilot period of at least 12 weeks would be necessary. Following a public tender it was decided that besides the operation phase, the subcontractor would also be responsible for the pre-selection of the car drivers. The subcontractor was supposed to detect license plates (of cars driving on a particular stretch of the highway) so potential participants could be approached. Even though the second pilot was planned for the beginning of 2011 the subcontractor did not succeed in detecting sufficient number plates because of technical reasons, so they could not perform a statistically reliable baseline measurement. Due to this the 2nd pilot had to be postponed. It resulted in a delay and subsequently the road works on the target stretch of highway were already nearly finished and the pilot became obsolete. Because of this the second pilot was finally stopped in January 2011.

Outcomes

Utrecht aimed to decrease the number of cars during rush hour by a least 1,000 vehicles during the period of construction works in Utrecht-West. The impact evaluation focuses on indicators in the transport sector. By distributing between 767 and 923 rewards per working day it was concluded that the traffic level was reduced between 500 and 700 cars during the morning rush hours. Thus the objective of decreasing 1,000 cars during the morning rush hour was not fully reached.

A Dutch study showed that it is difficult to measure the impacts of rewarding distribution due to the large number of external factors which are also influencing the traffic flow during the pilot project period. Despite the difficulties to draw the direct correlation between the implementation of the pilot-project and the results, three relevant observations on the traffic flow in Utrecht are positive and may be attributed as success of the MIMOSA measure. The first observation is that the traffic flow along the selected section of the highway A2 remained stable during the MIMOSA period. The second positive outcome was established in a national report of the Ministry of Traffic, which observed a reduction of travel times along the focused section of the A2 during the pilot project period. The third result showed an overall reduction of cars driving along the main traffic axes in the inner city within the period of the pilot project.

So despite the difficulty to evaluate the impacts the measure, the overall results showed that the objective to prevent the expected increase of traffic disturbances during the large-scale restructuration in Utrecht was achieved and it can be asserted that the rewarding system contributed to this success. 

The most challenging barriers in the implementation were related to the technical difficulties with the licence plate recognition. The subcontractor guaranteed 90 to 95% recognition of the licence plates. At the start they spotted only 40%. After some alterations they succeeded in improving the recognition and were obliged to extend the measurement period. Additionally, lease companies were not always willing to participate in the experiment, which reduced the number of potential participants. In Utrecht, a large number of car drivers are making their trip with a leased car.

The close cooperation between the region of Utrecht (BRU), the city of Utrecht and the national highway authority (RWS) was an important driver since it allowed the combining of different competencies. The participation of the highway authority allowed us to gain access to their license plate database, which was necessary to obtain the corresponding car drivers’ addresses, to pre-select and invite them to participate in the experiment.