EasyWay. Urban Travel Times on VMSs around Eindhoven. Evaluation Expert Group Document. Version 0.9. Issue: 1 st edition. Date: August 27 th, 2013

Transcription

1 EasyWay Evaluation Expert Group Document Urban Travel Times on VMSs around Eindhoven Version 0.9 Issue: 1 st edition Date: August 27 th, 2013 Issued by: Rijkswaterstaat (NL) Authors: Feiko van der Veen, Royal HaskoningDHV Henk Taale, Rijkswaterstaat

2 PREFACE In 2007 a new traffic management strategy was developed for the south-east region of the Brabant province. The 23 road managers in this region (Rijkswaterstaat, province and municipalities) work jointly for a better accessible south-east region of Brabant (in Dutch: Beter Bereikbaar Zuid-Oost Brabant, BBZOB). A self-regulating traffic system is the main principal of the new traffic management strategy: traffic makes route choices based on real-time traffic information, possibly leading to a traffic equilibrium on the road network. To strive for this goal, specific urban variable message signs (Dynamic Route Information Panels, DRIPs) with travel time information are used on the motorways in the neighbourhood of Eindhoven, the main city in this region. Since end 2009, this type of information is already visible in the form of texts on DRIPs in several Dutch regions, at some locations in graphical form (see also evaluation report CEN27 Travel Time Information on Dynamic Route Information Panels, October 5 th, 2012). The information around Eindhoven is displayed on DRIPs located right next to the hard shoulder. With the use of travel time information traffic is expected to spread, depending on its destination within Eindhoven. Previously, travel time information was only displayed regarding routes on the motorway network. Since mid 2012 also travel times for the main routes towards the urban ring road around the city centre can be displayed. And that part of the strategy is the subject of this evaluation study. This document describes the results of the evaluation study based on a traffic survey and a panel survey among road users in order to get insight in their perception and experience with travel time information on urban routes. The surveys were intended to provide information on the contribution of the travel time messages on route choice and to the improvement of the traffic equilibrium (better distribution of the traffic in the network). Urban Travel times on VMSs around Eindhoven August 27 th, 2013

3 TABLE OF CONTENTS REPORT TEMPLATE Key Evaluation Results Impact on Traffic Flow Impact on Safety Impact on Environment Other Key Results Description of the Problem Sites Issues Addressed Description of the ITS Project Service Area Key Words Objectives Systems and Technologies Applied Costs Status of the Project Evaluation Planned Timing and Type of Evaluation Research Questions Study Area for the Evaluation Expected Impacts... 12

4 4.5. Used Methods The Impact of the Project - Results Technical Performance Results Effects on Route Choice Opinion of Road Users and Road Director Reliability of Results Research Questions Answered Overall Assessment Safety Efficiency (Traffic Flow) Environment Road users opinion European Dimension: Transferability of the Results Urban Travel times on VMSs around Eindhoven August 27 th, 2013

5 REPORT TEMPLATE Project Code: CEN28 Project Name: Urban Travel times on VMS s around Eindhoven Area Code: CS113 EasyWay Region: CENTRICO Urban Travel times on VMSs around Eindhoven August 27 th, 2013

6 1. Key Evaluation Results This section presents a brief summary of the key results related to the EasyWay objectives and any other key results. The detailed results can be found in the next chapters. Travel time information for the (urban) routes to the Eindhoven city centre ring road was introduced in July 2012 on top of the existing text strategies for the Eindhoven region. The traffic related survey and evaluation was executed in the second half of 2012 in parallel to a panel survey among road users, traffic operators in the traffic management centre and road inspectors Impact on Traffic Flow No clear effects of the travel time information on the VMSs (called DRIPs in this report) on route choice were determined in this ex-post evaluation study. The number of situations when this could have happened (days with moderate and heavy congestion on one or both routes to the city ring road) was too limited. Moreover, besides small positive effects, opposite (negative) effects were determined as well. No negative effects of the displayed travel times were found for the undesirable urban access routes to the city centre ring road Impact on Safety Not evaluated Impact on Environment Not evaluated Other Key Results Analysis of the technical performance revealed a couple of problems related to some incorrect free flow travel times, swapped travel times of two routes and delay information that was displayed while congestion was already over. Some defect measuring points were also reported. Only 26% of the road users appeared to be familiar with the term Ring Eindhoven indicated on the DRIPs. The displayed texts seemed to reach only a minority of the road users (familiar with the road network and with DRIP messages) as the rest did not understand the indicated destination and/or which routes the information represented. Moreover, less than half of the respondents had a destination outside of the Eindhoven region. The majority of the road users, even with destinations within the Eindhoven region, preferred information on both the situation on the motorways as for the main urban arterials leading to the centre of Eindhoven. Urban Travel times on VMSs around Eindhoven August 27 th, 2013

7 2. Description of the Problem 2.1. Sites The Netherlands have around 100 Dynamic Route Information Panels (DRIPs), mounted above the roadway that provide information to road users in a textual way (3 lines of text). Another type of DRIP used within The Netherlands (> 100) and located right next to the hard shoulder, is used around Eindhoven for displaying travel time information in a combination of text and graphical information (bitmaps). Figure 2.1: Locations of the DRIPs on the motorways around Eindhoven with the four main (urban) routes from these DRIPs to the city centre ring road. Figure 2.2: Type of DRIP used around Eindhoven (left) and example of a travel time message (right). Urban Travel times on VMSs around Eindhoven August 27 th, 2013

8 2.2. Issues Addressed Until 2009, all DRIPs on the Dutch highways showed congestion information by number of kilometres congestion on the relevant routes to a specific destination point in the road network. However, road users were not aware of the resulting delay on their own route or the effect on the travel time to their destination. Since 2007, several pilot projects demonstrated the usability of algorithms that provided delay times on road sections. Together with the free flow times on the same sections, Rijkswaterstaat (RWS) was able to assemble the resulting travel times on these sections available to road users (see also see evaluation report CEN27 Travel Time Information on Dynamic Route Information Panels, October 5 th, 2012). It was decided in 2008 to start a project for implementing the switch from kilometres-of-congestion information to travel times in the entire country. Each DRIP would display the current travel times to a specific node in the road network, usually interchanges of highways, through two (and sometimes three) alternative routes. A test with a combination of motorway and urban travel times was started around Eindhoven. Travel times till the city centre ring road of Eindhoven were shown in case of congestion on the four main routes towards the city (figure 2.1). The DRIPs displayed both the travel time via the congested route and via an alternative route (figure 2.2). Five types of text strategies were in place with the following priority order: 1. Incidents / calamities 2. Road works 3. Dynamic traffic information a. Accessibility of economic top locations (approach roads Eindhoven, subject of this evaluation study) b. Upper-regional traffic (travel time from motorway interchange to motorway interchange) 4. Events 5. Pre-announcements and parking routes Eindhoven Messages with a higher priority came first compared to a message with lower priority. In case of congestion, dynamic traffic information (travel time messages) of routes to the city centre ring road (3a) had a higher priority than messages concerning congestion on the motorways around Eindhoven (3b). Urban Travel times on VMSs around Eindhoven August 27 th, 2013

9 3. Description of the ITS Project 3.1. Service Area The EasyWay Service areas are: Traveller Information Services, Traffic Management Services, Freight and Logistics Services, ICT Infrastructure. The main focus of the Travel Time on DRIPs Project around Eindhoven was to improve the quality of the existing traveller information on Dynamic Route Information Panels (Variable Message Signs, roadside system). Traffic related surveys were used and a survey among road users and road professionals (traffic operators and road inspectors) Key Words The following key words (highlighted) describe the nature of the Travel Time Project. Traveller Information Services Pre-trip Traveller Information On-trip Traveller Information Variable Message Signs Highway Advisory Radio Traffic Management Services Freight and Logistics Services ICT Infrastructure Variable Speed Limits Freight Management Data Management and Exchange Speed Control using ANPR Vehicle Safety Systems Use of Hard Shoulder Parking Areas DATEX II Automatic Incident Detection Hazardous Goods Monitoring and Tracking Traffic Management Plans Traffic Monitoring Driver Behaviour Use of CCTV Transport Security Control Centres Comprehension and Compliance Ramp Metering Traffic Management using Rerouting Enforcement Table 3.1: Services involved in the Travel Times Project (marked in yellow and bold) 3.3. Objectives The objective of the Travel Times on DRIPs Project around Eindhoven was to improve the quality of the existing traveller information on Dynamic Route Information Panels (DRIPs) by displaying additional messages regarding travel time on routes towards the city centre. As a result, a better spread of traffic over the road network was expected. Urban Travel times on VMSs around Eindhoven August 27 th, 2013

10 3.4. Systems and Technologies Applied The following systems and technologies were applied: The Dutch Motorway Traffic Management system to monitor traffic; Six dynamic route information panels (DRIPs, variable message signs) to display the travel times. Travel times on the information panels originating from the average car speeds, made available by processing the data from inductive loops in the road surface Costs The project costs were not available but modest: all roadside and central systems were already implemented and available. Only the algorithm for automatically activating messages on the DRIPs had to be developed. A rough estimation leads to a cost of ,- for this. The maintenance the 6 DRIPs used in this project costs about ,- per year Status of the Project In March 2013, the evaluation results regarding travel times on DRIPs Eindhoven were reported. At the time of writing, the installed measures are still operational and work properly after some adjustments due to the evaluation study. These adjustments relate to the errors in showing travel times on some of the DRIPs. Urban Travel times on VMSs around Eindhoven August 27 th, 2013

11 4. Evaluation Planned 4.1. Timing and Type of Evaluation The evaluation was carried out ex-post between November 2012 and March 2013, after implementation of the travel time project in July The quantitative evaluation included traffic related effects, based on traffic data and by using a before and after survey. No simulation was applied. The bases for the qualitative evaluation were surveys using a panel of road users and interviews with traffic operators at the traffic management centre and road inspectors Research Questions The following research questions were leading in the evaluation study. 1. Technical performance and application of the measure: a. How often were the text strategies (1, 2, 3a and 3b; see section 2.2) activated? Where and when? b. How often was the displayed message overruled (by the traffic operator, why and by which message? c. How long did it take before a message was displayed on the DRIP? 2. Effect on route choice: a. Was any change in traffic volume noticeable on the different displayed trajectories? When, where and to what extend? b. Was any change in traffic volume noticeable on other (undesirable) urban access roads to the city ring road? When, where and to what extend? c. Was any change in traffic volume noticeable on the city ring road? When, where and to what extend? 3. Effect on traffic flow: a. Was any change in travel time noticeable on the displayed trajectories, on other access roads to the city ring road and on the city ring road itself? When, where and to what extend? b. Was any change in vehicle hours lost noticeable on the displayed trajectories, on other access roads to the city ring road and on the city ring road itself? When, where and to what extend? 4. Possible improvements to enhance the effect of the measure: a. Did road users observe the DRIPs? b. Did road users understand the displayed message? c. Did road users understand the traffic situation? d. Were road users able to change route? e. Did road users want to change route? f. What were, based on the answers to these questions and in combination with the quantitative analysis (route choice and traffic flow), possible improvements to enhance the effect? Urban Travel times on VMSs around Eindhoven August 27 th, 2013

12 4.3. Study Area for the Evaluation The study area for the evaluation study is shown on the map in figure 2.1. It includes the motorways around Eindhoven (A2, A50, A58 and A67) and the four main arterials within the city of Eindhoven leading to the city ring road Expected Impacts No specific expected impacts were formulated beforehand. However, the overall expectation was that traffic spread over the available road network would increase Used Methods Both an analysis based on traffic data was used and a survey among road users including interviews with the road director. The methods used to answer the research questions (see section 4.2) were as follows. 1. Technical performance and application of the measure For questions 1a and 1b, the loggings of the DRIP-activation system were collected and categorised. Additionally, for question 1c the points in time of a delay (as recorded in the national traffic database, NDW) were compared to the points in time of changed messages on the DRIPs. 2. Effect on route choice In the analysis a before and after survey was carried out: the before survey based on the period February up to and including April 2012, the after survey September up to and including November Both for before and after survey a selection of days was carried out, taking the following into account: extreme weather conditions, holidays and incidents. This resulted in sufficient usable days: >50 for the before situation and >60 for the after situation. Per DRIP all periods when travel time was displayed were subdivided in one of the following categories: (1) no congestion, (2) very light congestion, 1-2 minutes delay, (3) light congestion, 3-5 minutes delay, (4) moderate congestion, 6-10 minutes delay and (5) heavy congestion, more than 10 minutes delay. For each combination of these four categories, the average splitting fraction was calculated by using the traffic volumes on both displayed routes directly after the DRIP (decision point) and just before the city centre ring road. The expectation was that more traffic would follow the less congested (displayed) route. This analysis was done for morning peak, evening peak and in-between as travel patterns could change according to the time of day. 3. Effect on traffic flow These questions would only be answered in case of clear route choice effects due to the DRIP. 4. Possible improvements to enhance the effect of the measure The results of a panel survey among road users were combined with the quantitative results of the traffic analysis. Additional interviews with employees of Rijkswaterstaat were carried out to investigate their opinion and estimation of the effect of the measure. Urban Travel times on VMSs around Eindhoven August 27 th, 2013

13 5. The Impact of the Project - Results 5.1. Technical Performance Below the main conclusions regarding technical performance based on DRIP loggings. Travel times towards the city centre ring road During the after situation merely light delays were shown on the routes towards the Eindhoven city ring road. Heavy congestion occurred in a relatively limited way. On the DRIPS north of Eindhoven travel times were hardly displayed while congestion was apparent. Free flow travel times were probably not adjusted in the right way. The A2-south DRIP constantly displayed the travel times of the two routes to the city ring road in a swapped way. This DRIP showed a delay of 3 minutes for one of the two routes for a longer period while there was no congestion according to the traffic data from the national database. Manual messages were not activated in a proper way. Due to missing data in the national traffic database, a clear view on the delay within the information chain was not possible. A time difference between first appearance of congestion and the moment of displaying on the DRIP was indicated as roughly 3-5 minutes. Travel times upper-regional traffic Several DRIPs showed a delay of 1 minute during a very long period for the upper-regional traffic (transit traffic with origin and destination outside the region), especially during low traffic and during the night. Probably (slower) heavy trucks were the cause for this phenomenon. Adjustment of the free flow travel time would solve this problem. Defect measuring points had led to the announcement no info on one of the routes and no upperregional messages at all on another DRIP. Necessary adjustments on the free flow travel times were determined for the algorithms of two DRIPs at the northern side of Eindhoven: travel times were displayed for quite different durations Results Below, the results of the evaluation are described per evaluated feature. The descriptions are the result of the (quantitative) traffic analysis and the (qualitative) road user survey EFFECTS ON ROUTE CHOICE Delays on one or both routes and a possible change in route choice was determined for the DRIPs that showed travel time information to the city centre ring road of Eindhoven. Focus in the analysis was on situations with expected large changes in route choice, for instance no or light congestion on one route and moderate or heavy congestion on the other route. Splitting fractions Figure 5.1 shows the used measuring points (in red) for the determined splitting fractions (percentage of traffic following routes 1 and 2 after the decision point, being the DRIP). In some cases alternative measuring points (in yellow) in the vicinity were used. Urban Travel times on VMSs around Eindhoven August 27 th, 2013

14 Measuring Meetpunt splitsingsfractie point Alternative Afgeleid meetpunt measuring point Figure 5.1 Overview of measuring points for determining splitting fractions The analysis of the splitting fractions was carried out for the morning and after peak hours and for the before and after situation. For the before situation travel times were calculated based on the national traffic database. For the after situation the displayed travel times were used. In some cases traffic took the less congested route, but also the opposite was found. However, the changes in route choice were small (change in splitting fraction of 0-2%) and occurred in both before and after situation. The reason for this minor effect was probably the small number of situations with moderate or heavy congestion on one or both of the routes. Conclusion: the analysis of the splitting fractions at the six DRIPs did not result in clear changes in route choice due to the messages on the DRIPs. Changes due to heavy congestion An additional detailed analysis for some situations with heavy congestion on one of the two routes was carried out as well. Below the results of two situations. Urban Travel times on VMSs around Eindhoven August 27 th, 2013

15 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% DRIP DRIP A2 A2 Noord North Percentage verkeer traffic naar to Route Route 1 1 Meting voor de Ring Measured before the Ring geen file route 2 No congestion route 2 file route 2 Congestion route 2 Figure 5.2 Analysis route choice DRIP A2-north, congestion on 23 November 2012 Just before and at the beginning of the congestion at 17:30 (figure 5.2) less traffic followed route 1 (and as a result more traffic the congested route 2). After a certain period this situation changed. This was analysed as an effect of the DRIP: after displaying heavy congestion on route 2 more traffic chose for route 1. A closer analysis revealed, however, that more traffic was present on route 2 at that moment, which was the cause for the congestion there. As a result, the message with heavy congestion did not lead to an increase of traffic volume on the other route: the DRIP did not have a clear effect. 70,0% 60,0% 50,0% 40,0% 30,0% 20,0% 10,0% 0,0% DRIP A67 West Percentage verkeer traffic naar to Route 1 1 Measured Meting voor before de the Ring Ring 16:20 16:35 16:50 17:05 17:20 17:35 17:50 18:05 18:20 18:35 18:50 19:05 19:20 19:35 19:50 No geen congestion file route route 22 Congestion file route route 2 2 Figure 5.3 Analysis route choice DRIP A67-west, congestion on 27 November 2012 On the A67-west a slight increase was analysed for traffic following route 1 at the beginning of (displayed) congestion on route 2 (see figure 5.3). However, next this percentage decreased again, followed by an increase after the congestion at route 2 was over. This seemed to be a normal fluctuation rather than an effect of the DRIP message. Also no effect was seen at the decision point directly after the DRIP. Urban Travel times on VMSs around Eindhoven August 27 th, 2013

16 Undesirable urban access roads Displaying travel times concerning routes to the city ring road could have led to undesirable changes in traffic on other routes. Figure 5.4 shows the for this study selected urban roads leading to the city centre. Figure 5.4 Overview of undesirable access roads to the city centre of Eindhoven Huizingalaan For the Huizingalaan in the north traffic data in the after situation was too deviating to draw conclusions about the influence of the DRIPs. Noord-Brabantlaan Traffic volume (veh/h) Traffic volume Noord-Brabantlaan related to DRIP message A58 No travel time No congestion Very light Light Moderate Heavy morning in-between afternoon evening&night Period Figure 5.5 Traffic volumes on the Noord-Brabantlaan (city-in) in relation to travel time on the Tilburgseweg as displayed on the A58 DRIP Urban Travel times on VMSs around Eindhoven August 27 th, 2013

17 For the Noord-Brabantlaan in the west a comparison was made between the traffic volumes on that road and the travel times on the alternative route via the Tilburgseweg, just north of the Noord-Brabantlaan. Both roads are the shortest routes to the city ring road coming across the DRIP at the A58 (north-west of Eindhoven). Figure 5.5 gives the impression that the displayed congestion on the Tilburgseweg (the normal access road to the city ring road) caused an increase at the Noord-Brabantlaan. However, the higher travel time information was only displayed for a relative short time. Thus, no solid comparison was possible. Professor Holstlaan Traffic volumes during after situation (September till October 2012) were higher than in the before situation (see figure 5.6). Traffic volume (veh/h) Traffic volume Professor Holstlaan (city-in) February March April September October November Figure 5.6 Traffic volume on Professor Holstlaan in before and after situation The increase in traffic flow on this road could have been the effect of the travel times on the DRIPs. A comparison was made between the average traffic volumes in the after situation on this road and no congestion on the normal route displayed on the A67-west DRIP with a situation of moderate or heavy congestion (figure 5.7). In case of moderate and heavy congestion no clear increase in traffic volumes on the Professor Holstlaan was determined, thus no negative effects due to the travel times on this DRIP. Traffic volume Professor Holstlaan related to DRIP message A67-west Traffic volume (veh/h) Intensiteit (mvt/uur) morning in-between afternoon evening&night Period No travel time No congestion Very light Light Moderate Heavy Figure 5.7 Traffic volumes on the Professor Holstlaan (city-in) in relation to travel time on the Aalsterweg as displayed on DRIP A67-west Urban Travel times on VMSs around Eindhoven August 27 th, 2013

18 Karel de Grotelaan Traffic volumes at the Karel de Grotelaan in before and after situation were quite similar. Also here no visible relation was seen between the displayed delays on the DRIPs and the traffic volumes on this undesirable road. However, the average traffic volumes were lower in situations when no travel times were displayed on the DRIP A67-west. A possible explanation is that in case of congestion on the displayed routes, the traffic volumes on the Karel de Grotelaan were also considerable. No clear relationship was demonstrated between congestion displayed on the A67-west DRIP and increasing traffic on the Karel de Grotelaan. Traffic volume Karel de Grotelaan related to DRIP message A67-west Traffic volume (veh/h) morning in-between afternoon evening&night Period No travel time No congestion Very light Light Moderate Heavy Figure 5.8 Traffic volumes on the Karel de Grotelaan (city-in) in relation to travel time on the Aalsterweg as displayed on DRIP A67-west Change of traffic volumes on city centre ring road Eindhoven Changes in route choice due to the DRIPs also could have led to changing traffic volumes on the city ring road Eindhoven. For the analysis the measuring points as indicated in figure 5.9 were used, both on the inner ring and the outer ring. It concerned two streets: Pastoriestraat and Leostraat. Measuring point Figure 5.9 Measuring points at the city ring road Eindhoven Urban Travel times on VMSs around Eindhoven August 27 th, 2013

19 In the Pastoriestraat traffic volumes in before and after situation were quite similar. In the Leostraat during the after situation on average 4% higher, probably caused by seasonal influences. Moreover, the analysed relationship between traffic volumes in the Leostraat and the displayed delays on the DRIP A67-east also did not reveal a clear effect of the DRIPs on the traffic volumes on the city ring road OPINION OF ROAD USERS AND ROAD DIRECTOR Results of road user panel survey The questions for the participants in the survey were arranged according to the used sequence (1) Observation, (2) Comprehensibility, (3) Ability to act and (4) Will to act. In general Destinations of the participants in the survey were divided into almost 50% with a destination outside the region and slightly over 50% with different destinations within the Eindhoven region. Figure 5.10 shows how often and when the participants travelled in the Eindhoven region. 25% of the total number of drives were made almost on a daily basis, of which almost 60% during the morning peak hours. The number of drives in the in-between period (between the peaks) was higher when people travelled less often in the region. 100% How often and when did you travel in the Eindhoven region? 90% 11% 80% 38% 70% 60% g e ta n 50% rce e P 40% 31% 13% 63% 78% 83% In-between hours (outside peaks) Evening peak (15:00-19:00) Morning peak (06:00-10:00) 30% 58% 50% 17% 20% 8% 3% 10% 20% 14% 14% 0% almost couple of weekly couple of couple of daily times/week times/month times/year Figure 5.10 Overview of frequency and time of day for road users to travel in the Eindhoven region Road users who travel near Eindhoven on an almost daily basis are mainly commuters travelling during the peak hours. These road users were considered to be the most frequent (and experienced) users of the travel time information on the DRIPs. The survey showed that they gained their experience on times when the DRIPS were displaying useful information during the peak hours. Observation 81% of the participants in the survey had seen one or more of the DRIPs around Eindhoven, but almost 20% of them could not remember at which location(s). Of all participants only 16% had noticed that travel time information to the city centre ring road was added since the introduction in July Around 50% Urban Travel times on VMSs around Eindhoven August 27 th, 2013

20 had noticed that the DRIPs showed travel time information all the time. It can be concluded that most of the participants had noticed the DRIPs but not the difference in type of information nor the fact if any type of information was displayed. Comprehensibility Almost 60% of the participants responded on the question of type of information displayed: travel time on the motorways. And 25% gave the answer: travel time on the motorways and travel time to the city centre ring road. Surprisingly, 71% thought that Ring Eindhoven is the collection of motorways around Eindhoven and only 26% gave the correct answer: the city ring road (see figure 5.11). The percentage of road users who were familiar with the Eindhoven region was slightly higher (29%), but still very low. Figure 5.11 Map in questionnnaire with possible choices of Ring Eindhoven (green=motorways, yellow=ring Eindhoven, red=inner city ring) Ability to act More than 60% of the respondents was able to change route as they indicated to have enough time to do so and around 25% of them did not. The frequency of passing by the DRIP did not seem to influence the time left for changing route, but the younger they were, the more time they had (figure 5.12). Did you have enough time for changing route after seeing a DRIP? 80,0% 70,0% 60,0% 50,0% 40,0% 30,0% 20,0% 10,0% 0,0% Yes No Don t know Age Age Age 50+ Figure 5.12 Overview of frequency and time of day for road users to travel in the Eindhoven region Urban Travel times on VMSs around Eindhoven August 27 th, 2013

21 Will to act The percentage of road users who did not change their normal route was 17% in case the alternative route was 5 minutes faster. More than half of this group preferred to follow their fixed route and slightly more than one-fifth indicated to expect another travel time than displayed. The latter group of respondents (4% of the total of participants) did have any confidence in this type of messages at all. Around 55% never changed their route as a result of the DRIPs, 13% just once and 32% more than one time. This latter percentage is surprisingly higher than the percentage of people that were able to indicate Ring Eindhoven in the correct way. The road users who changed route experienced the alternative as presented in figure What was your experience with the alternative route? Don t know 2% Something else 4% I could not find the way and did not have travel time advance 4% Alternative route was not faster 31% No congestion indeed 59% 0% 10% 20% 30% 40% 50% 60% 70% Figure 5.13 Experience of alternative route in case of changed route In order to find out the reach of the DRIPs and the displayed travel times to the city centre ring road, the percentage of respondents was determined who gave the correct answer, given a number of crucial questions. Table 5.1 presents the results. Per question the number of people is a subset of the people who gave the correct answer to the previous question. The conclusion is that only 2% of the road users with the Eindhoven region as destination understood the displayed message completely, were able and willing to change their route and took the fastest route as a result. Thus, the reach of DRIPs seems to be limited. Question % remaining respondents Start 100% Destination Eindhoven region 54% City Ring Eindhoven correctly pointed out 13% Knew which exit numbers were often used 7% Did understand the DRIP messages well 3% Did have enough time to make a choice 2% Chose for the fastest route in case of 5 minutes time difference 2% Table 5.1 Reach of the DRIP in terms of percentage of right knowledge and choices Urban Travel times on VMSs around Eindhoven August 27 th, 2013

22 Opinion of road director The operators in the traffic management centre were informed quite often by road inspectors and road users about the messages on DRIPs. Many road users had a misperception about the Ring Eindhoven (city centre ring road). The text Eindhoven Centre would have been more appropriate. Also the displayed travel times (indicated as free flow travel time x plus delay time y, see figure 5.14) was too ambiguous. Addition of min between x and y would be clearer, but needs more space on the DRIP which is often not available. Because the priority for displaying travel time to the city centre ring road was higher than for congestion or accidents on the A2 motorway, road users with origin and destination outside of the region were quite often confronted with congestion on the A2. They could not avoid this congestion by following the alternative route (N2 directly in parallel to the A2), because the through route was not displayed in case of congestion on the routes leading to Ring Eindhoven. Figure 5.14 Example of delay time message 5.3. Reliability of Results In order to get reliable answers for the research questions, great efforts were done in the ex-post evaluation study to reduce or even exclude (external) sources of bias. First of all, traffic volumes in before and after situation were enough comparable (no influence in terms of changes due to economic effects). A selection of days was carried out, taking the following into account: extreme weather conditions, holidays and incidents. This resulted in sufficient days usable for the analysis: >50 for the before situation and >60 for the after situation. This analysis was done for morning peak, evening peak and in-between time separately. Even with DRIP loggings that were lacking for some specific (short) periods, an analysis was possible for the technical functioning of the systems Research Questions Answered See section Overall Assessment Below the main finding of the evaluation are summarised in terms of contribution to the European objectives SAFETY Not evaluated separately EFFICIENCY (TRAFFIC FLOW) No clear effects of DRIPs on route choice were determined in this ex-post evaluation study. In some situations with heavy congestion on the routes leading to the Eindhoven city ring road, traffic flow on the Urban Travel times on VMSs around Eindhoven August 27 th, 2013

23 congested route decreased. However, the number of these cases with moderate and heavy congestion was limited. Frequently, opposite effects were determined as well, even based on analysis of the before survey. On the undesirable urban access routes to the city centre ring road no negative effects of the displayed travel times were found. Traffic flow did not increase here due to the addition of this type of travel information to the total set of text strategies for the Eindhoven region ENVIRONMENT Not evaluated separately ROAD USERS OPINION A major conclusion is that only 26% of the road users was familiar with the term Ring Eindhoven. Also most of the road users did not know which exit they normally took. Thus, the displayed DRIP texts did seem to reach only a minority of the road users as the rest did not understand the indicated destination and/or which routes the information represented. Moreover, almost half of the respondents had a destination outside of the Eindhoven region. Thus, the displayed information was not important for them either. Looking at the respondents with sufficient knowledge of the road system, familiarity with DRIPs and willingness to change route when travel time to the Eindhoven centre ring road was displayed, only 2% of the total group of respondents remained. The majority of the road users, even with destinations within the Eindhoven region, preferred information on both the situation on the motorways as for the main arterials leading to the centre of Eindhoven. Urban Travel times on VMSs around Eindhoven August 27 th, 2013

24 6. European Dimension: Transferability of the Results The following conclusions can be made regarding the applicability of the results of the Travel Times project in the Netherlands to other similar implementations in other countries: Road users appreciated travel times highly. Because of this preference, and the fact that travel time information is being used in other countries as well, similar implementations of travel time information should be promoted. Displaying default (free flow) travel times supplemented with extra travel times is even more appreciated. This requires, however, specific algorithms and additional fine tuning. The combination of texts and graphics for travel times on congested routes is only understood by a minority of road users, most of them commuters. For the rest of the road users, including foreign drivers, the displayed information is superfluous. Note: most of the DRIPs / Variable Messages Signs in other countries are not capable of displaying this type of information or road authorities are not allowed to put similar information on their VMS s. Although the characteristics of road users in other European countries differ from those in The Netherlands, displaying traveller information in any form will be beneficial: either road users regards this information as extra and comfortable (in line with their expectations) or they could decide to change their initially chosen route because of congestion reasons. Urban Travel times on VMSs around Eindhoven August 27 th, 2013