EasyWay. Traffic Management Scenarios on the A15 Motorway (Rotterdam) Evaluation Expert Group Document. Final Version. Issue: 2 nd edition

Transcription

1 EasyWay Evaluation Expert Group Document Traffic Management Scenarios on the A15 Motorway (Rotterdam) Final Version Issue: 2 nd edition Date: August 27 th, 2013 Issued by: Rijkswaterstaat (NL) Authors: Feiko van der Veen, Royal HaskoningDHV Henk Taale, Rijkswaterstaat

2 PREFACE In 2008, the South-Holland region decided to invest substantially in regional traffic management. The municipalities of Rotterdam and The Hague, the province of South-Holland, Rijkswaterstaat (the operator of the motorways) and the metropolitan districts of Rotterdam and Haaglanden (The Hague region) have drawn up a programme for the realisation of roadside systems, for tactical frameworks and for designing and implementing joint traffic management scenarios. Each of the road managers in the South-Holland region has its own traffic management centre, but for traffic problems that hit more than one road authority, the Region Desk was established. In this way, the responsibility for cooperation and coordination between the existing traffic centres obtained an own (explicit) position. Since September 2011, the Region Desk is in operation, as a separate team with its own desk in the traffic management centre South-West Netherlands, located south of Rotterdam. In situations of regional traffic problems, the Region Desk is able to activate pre-defined traffic management scenarios in order to make use of the available capacity of the entire network of motorways and secondary roads in a more optimized way. In case of the scenarios for the Rotterdam harbour (motorway A15), variable message signs were used for displaying congestion information on the A15 motorway including preferred routes on the secondary road network. At the same time, traffic lights on the secondary roads were modified in order to increase capacity on the alternative routes where and when needed. Based on the CCTV images and constant monitoring of the traffic, the regional traffic operators conceived the scenarios to have positive effecs. However, this impression was not quantified yet. This report describes the results of an ex-post evaluation study, focussing on the analysis of the effects of two harbour scenarios on traffic throughput of both the A15 motorway and the secondary road network. The report is an English summary of the Dutch report Evaluatie regelscenario s A15, written by Goudappel Coffeng, commissioned by BEREIK!, November Traffic Management Scenarios on the A15 Motorway (Rotterdam) 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 7 2. Description of the Problem Site Issues Addressed 8 3. 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 Objectives for the Evaluation Research Questions 13 Traffic Management Scenarios on the A15 Motorway (Rotterdam) March 5 th, 2013

4 4.4. Study Area for the Evaluation Expected Impacts Used Methods The Impact of the Project Results Technical Performance Results Road network performance Traffic flow on A15 and secondary roads Route choice effects Overall conclusions Reliability of Results Research Questions Answered Overall Assessment Safety Efficiency Environment European Dimension: Transferability of the Results Annex 1: MoniGraph Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

5 REPORT TEMPLATE Project Name: Traffic Management Scenarios on the A15 Motorway (Rotterdam) Project Code: CEN38 Area Code: CS222 EasyWay Region: CENTRICO Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

6 1. Key Evaluation Results This section presents a brief summary of the key results, specifically related to the EasyWay objectives. The detailed results can be found in the next chapters. Brief project description A set of traffic management scenarios was developed in order to be more in control of traffic flow in the Rotterdam region. Two specific scenarios for the Rotterdam harbour area were developed: harbour-in (morning peak) and harbour-out (evening peak). These two scenarios were evaluated ex-post mid The basis of these two traffic management scenarios is to promote the use of alternative routes in case of obstructed traffic flow or congestion on the A15 motorway with the objective of facilitating the in-flow and out-flow of the Rotterdam harbour area. The default situation (normal traffic) is as follows: 15 variable message signs (VMS), on the road network around the A15 motorway in the harbour area, display the actual travel times for the standard route on the A15 and the corresponding alternative route on the secondary road network. In case of congestion (regular or due to incidents) on the A15, directive route information is used to relieve the A15 by advising traffic on the A15 with a local destination to leave the A15 on an earlier occasion. At the same time, traffic heading towards the A15 is advised to keep on the secondary road network in order to enter the A15 later and if possible in front of the queue. Traffic lights on the secondary roads are adjusted temporarily to facilitate the alternative routes. When the traffic flow on the alternative routes drops below a certain threshold level, or when the bottleneck on the A15 disappears, the scenario is ended. The objective of the ex-post evaluation study was to determine the traffic related effects of the (coordinated) harbour scenarios during regular traffic situations. The evaluation study focused on three levels: (1) road network performance, (2) traffic flow on A15 and secondary routes, and (3) route choice effects Impact on Traffic Flow The ex-post evaluation of the developed traffic management scenarios showed the following results: Road network performance: the number of vehicle hours delay dropped clearly at this highest aggregation level, compared to the before situation by about 3%. However, the number of vehicle kilometres decreased as well by about 1%. Apparently there was less traffic in the after situation, at least on the A15 motorway, but also (surprisingly) on the secondary road network. Due to insufficient data, it could not be determined whether the decrease in vehicle hours delay was caused by the scenarios or the decrease in traffic. Traffic flow on A15 and secondary routes: no clear difference between before and after situation. The median value of the congestion rate 1 and number of vehicle hours delay were slightly lower than during the before situation, but the variation in both before and after situation was large. The difference was therefore not significant. The development of the speed in time on the A15 was slightly lower and more equal than in the before situation. Only on one section of the A15 travel time clearly decreased during 1 Congestion rate (in Dutch: filezwaarte) is the product of length and duration for a specific traffic queue, expressed in kilometre minutes. For example: a congestion rate of 15 kilometre minutes could be both a queue of 15 kilometres during 1 minute as a queue of 3 kilometres during 5 minutes. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

7 the evening peak (by more than 4%). This was not due to the scenarios, because the number of vehicle kilometres and volumes on the secondary road network decreased clearly as well. Route choice effects: with normal traffic flows, the effect of directive route information on VMS s was limited and not significant. During normal workdays, road users are usually quite familiar with congestion patterns and know very well when to follow alternative routes. VMS s had therefore no effect on route choice as the information only confirmed their assumptions. However, in non-regular situations (such as accidents or partial road closures) the effect was very clear. When road users were informed about an accident or capacity restriction, considerable shifts in route choice were noticed, as expected. Overall, the effects of the activated traffic management scenarios were limited Impact on Safety Not evaluated Impact on Environment Not evaluated Other Key Results The following recommendation was a by-result of the evaluation study: For the purpose of solid conclusions, the duration of the measuring period(s) should be extended or at least large enough. For the analysis in this study only 30 workdays for both before and after situation were available with lots of fluctuation due to the large daily variation in traffic. Beforehand it was determined that this should be enough, but it appears that twice as long measuring periods are advised for this type of evaluation study, to reduce the variation within the before and after situation. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

8 2. Description of the Problem 2.1. Site The A15 is the major motorway to get to the harbour area (and back again). The A15 connects the hinterland to Rotterdam and its harbours. The study area for this evaluation study is indicated with a red line in figure 2.1. A15 A15 A15 Figure 2.1 Study area of the evaluation 2.2. Issues Addressed Destination traffic for the Rotterdam harbour and beyond (Maasvlakte, west of Rotterdam) suffers from congestion on the A15 almost every working day, especially during peak hours. Two specific traffic management scenarios for the harbour area were developed to control traffic flow in the A15 area by facilitating the in-flow and out-flow through intensifying the use of alternative routes in case of decreased traffic flow or congestion on the A15 motorway. Traffic Management Scenarios on the A15 Motorway (Rotterdam) 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. In the project involved traffic management scenarios on the A15 motorway (traffic management services) were developed and implemented. Traffic management scenarios were put in operation by traffic operators at the Region Desk, based on current, measured traffic situation. Each scenario included a set of measures like activation of VMS s and/or adjustment of traffic lights Key Words The following key words (highlighted) describe the nature of the project and the applications used. Traveller Information Services Pre-trip Traveller Information On-trip Traveller Information Variable Message Signs Motorway 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 project Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

10 3.3. Objectives Dutch transport and traffic policy emphasises a better use of the existing infrastructure, as building new roads is too expensive and takes too much time due to procedures related to spatial and environmental conditions and pricing is politically not an option. The municipalities of Rotterdam and The Hague, the province of South-Holland, Rijkswaterstaat and the metropolitan districts of Rotterdam and Haaglanden (The Hague region) have drawn up a programme for the realisation of roadside systems, for tactical frameworks and joint traffic management scenarios. Their objective is to make better use of the entire existing road infrastructure, motorways including secondary road network, in a more optimized way. The joint road managers have established the Region Desk, a separate desk in the traffic management centre South-West Netherlands, for network wide traffic management. Two specific scenarios for the Rotterdam harbour area were developed and implemented to control traffic in the A15 area: harbour-in (morning peak) and harbour-out (evening peak). Variable message signs (VMS s) were used for displaying congestion information on the A15 motorway including preferred routes on the secondary road network. And traffic lights on the secondary roads were adjusted in order to increase capacity on the alternative routes where and when needed. The objective of the Traffic Management Scenarios project was to keep the A15 motorway in the harbour area running smoothly and without big problems by facilitating the in-flow and out-flow through intensifying the use of alternative routes in case of decreasing traffic flow or congestion on the A15 motorway. During normal traffic flow, the 15 variable message signs (VMS) in the area displayed the actual travel times for the standard route on the A15 and for the corresponding alternative route on the secondary road network. With congestion on the A15, directive route information was used to relieve the A15 by advising traffic on the A15 with a local destination to leave the A15 on earlier occasion. At the same time, traffic heading towards the A15 was advised to keep on the secondary road network in order to enter the A15 if possible in front of the queue. Precondition for activation of a scenario was that travel time on the alternative routes was acceptable. The EasyWay projects overall objectives which are expected to be achieved by 2020 are as follows: 25% improvement in road safety by 2020, 25% decrease in congestion, facilitate travel and mobility of people and goods by 2020, 10% reduction in the impact on the environment by The Traffic Management Scenarios project for the A15 motorway aims mainly to contribute to the EasyWay objectives by a reduction in congestion Systems and Technologies Applied The set of previously installed and during the project used traffic management measures included among others: 15 VMS s on the A15 motorway and on main secondary roads leading to the A15 as well as in the harbour area. Traffic lights on the alternative routes parallel of the A15 and on the main secondary roads leading to the A15. The VMS s were provided with (predefined) texts and images and the traffic light were adjusted by selection of more appropriate signal timing schemes. The two traffic management scenarios were developed to operate the different traffic measures in a coordinated way. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

11 Morning peak The timeframe for scenario harbour-in was limited to workdays between 5.30 and 9.30 hrs. (morning peak). Figure 3.1 shows the overview of the routes for scenario harbour-in morning peak. The alternative routes are indicated with R05 (green) and R06 (blue), the A15 motorway in red. This scenario was usually activated when bottleneck KT04 occurred. Figure 3.1 Overview routes harbour-in (morning peak) Evening peak The timeframe for scenario harbour-out was limited to workdays between and hrs. (evening peak). Figure 3.2 shows the overview of the routes for scenario harbour-out evening peak. The alternative routes are indicated with R08 (blue), R09 (green), R10 (green), R11 (blue), R15 (black) and R16 (purple), the A15 motorway in red. Activation of this scenario for routes R08, R09 and R10 was usually triggered by bottleneck KT02 in the evening peak, and for routes R15 and R16 by bottleneck KT05. Figure 3.2 Overview routes harbour-out (evening peak) Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

12 3.5. Costs The project costs were not available but modest: all roadside systems were already implemented and available. Only the traffic management scenarios had to be developed and implemented. The costs for this is estimated to be ,-. The project uses 15 VMS s of a certain type. The maintenance costs of these VMS s is estimated to be ,- per year Status of the Project At the time of writing (March 2013), the Traffic Management Scenarios project for the A15 is finished. The scenarios are still operational and work properly. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

13 4. Evaluation Planned 4.1. Timing and Type of Evaluation The evaluation study was carried out ex-post in May and June 2012 and included a 6 week period of collecting traffic data and loggings of the different central systems and roadside systems. The traffic management scenarios were alternating on and off. So 1 week without scenarios and week using the scenarios. After that the evaluation continued with the analysis of traffic related effects Objectives for the Evaluation The overall objective of the ex-post evaluation study was to determine the traffic related effects of the two traffic management scenarios for traffic in the study area (A15 near Rotterdam harbour area) during regular and non-regular traffic situations Research Questions No explicit research questions were derived from the report of the evaluation study. However, the evaluation included three main levels with corresponding indicators: 1. Road network performance: vehicle hours delay, vehicle kilometres. 2. Traffic flow on A15 and secondary routes: traffic volumes, travel speeds, travel times, vehicle hours delay, congestion rate. 3. Route choice effects: turning percentages Study Area for the Evaluation The study area for the evaluation is indicated in figure 2.1 with the red line. It includes the A15 motorway and connecting secondary roads in the harbour area, south-west of Rotterdam Expected Impacts Only for level 1 (road network performance) the expected impacts as a result of the scenarios were described in the evaluation report: vehicle hours delay in the study area will decrease, and vehicle kilometres on the A15 motorway will decrease while vehicle kilometres on the secondary roads will increase. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

14 4.6. Used Methods The following sources were used for traffic data collection: Loop detector data of the A15 motorway, obtained through the Rijkswaterstaat MoniCa database. The Rijkswaterstaat tool MoniGraph (see Annex) was used for processing these data into visible tables and graphs. Data, primarily traffic volumes, from the national database for road traffic data (in Dutch NDW, Nationale Databank Wegverkeersgegevens) for analysis of the secondary road network. Traffic lights counts for analysis of route-choice effects based on turning percentages. Roportis data (monitoring system of the Port of Rotterdam organisation) for analysis of vehicle hours and vehicle hours delay on some harbour roads. VMS loggings for determining exact start and end times of scenarios. Also incidents, bridge openings and other disturbing events could be distinguished through these loggings. Region Desk loggings: these daily reports included weather circumstances and information about severity and handling of traffic accidents. Non-regular days were filtered out. This resulted in a number of days with usable traffic data as indicated in table 4.1. In total 4 days with non-regular traffic situations (with accidents, partial road closures, adverse weather situations) were identified for analysis of effects during days with unusual traffic patterns. Morning Evening before after before after Monday Tuesday Wednesday Thursday Friday Total Table 4.1 Overview of days with usable traffic data The evaluation study compared the values of the traffic indicators of the before and after situations during the analysis. Based on the comparison conclusion were drawn about the effects of the scenarios. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

15 5. The Impact of the Project Results 5.1. Technical Performance The VMS s, traffic light systems and the scenarios system performed well during the period of data collection. No malfunctioning was reported Results ROAD NETWORK PERFORMANCE The expected effect of the scenarios was that relatively more traffic would follow the secondary road network and therefore the number of vehicle hours delay on the A15 would decrease. This analysis focused only on the regular workdays with normal traffic patterns, that is to say with traffic patterns that fall into a certain bandwidth. Days with extreme traffic conditions (large incidents and bad weather conditions) are left out. Table 5.2 shows the determined vehicle kilometres and vehicle hours delay for three sections of the A15 motorway, corresponding to the three different combinations of alternative routes: (1) R05 and R06, (2) R08, R09 and R10, and (3) R15 and R16. These combinations were called connections in the evaluation study. The presented values are the average values of morning peak and evening peak. Routes indicator before after difference Route 05 and 06 vehicle kilometres 152, , % vehicle hours delay % Route 08, 09 and 10 vehicle kilometres 95,314 94, % vehicle hours delay % Route 15 and 16 vehicle kilometres 144, , % vehicle hours delay 1,542 1, % Table 5.2 Results of the analysis for distinguished sections of the A15 Based on the processed and analysed data from NDW and Roportis sources, the results for the secondary network were as presented in tables 5.3 (vehicle kilometres) and 5.4 (vehicle hours delay). Connection before after difference Route 05 15,598 14, % Route 06 47,947 48, % Route 08 70,796 70, % Route 09 9,095 8, % Route 10 58,149 57, % Route 15 8,869 8, % Route 16 34,169 34, % Table 5.3 Results of the analysis for vehicle kilometres on secondary road network Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

16 Connection before after difference Route % Route Route Route % Route Route % Route % Table 5.4 Results of the analysis for vehicle kilometres lost on secondary road network Routes 05 and 06 These routes were both alternative routes for the A15 in the morning peak (westbound), but with different origins: traffic already on the A15 motorway (R05) and urban traffic (R06). Vehicle kilometres increased on R06 and decreased on R05. Also the number of vehicle hours delay decreased on R05. On the A15 motorway the decrease in vehicle hours delay was as expected - even higher. The standard deviation of vehicle hours delay on the A15 appeared to be 35% of the total number of vehicle hours delay, with the conclusion that the difference between before and after situation was not significant. Routes 08, 09 and 10 On these alternative routes (evening peak, eastbound) the vehicle hours delay decreased on the A15 as well as on de secondary road network, and on the latter relatively more. This did not match with the expectation that traffic would prefer to follow the alternative routes. The differences were explained as the result of a high variation in traffic flow between the workdays. The number of available separate workdays was too small for a more detailed analysis. The standard deviation of vehicle hours delay on the A15 was almost a high as the number of vehicle hours delay. The differences between before and after situation therefore were small compared to the variation between the analysed days. Routes 15 and 16 Similar results for these routes were analysed as for routes 08, 09 and 10. Conclusions at network level At the highest aggregation level, a clear decrease was determined of vehicle hours delay in the study area of about 3%. However, the number of vehicle kilometres in the after situation was also lower than in the before situation (about 1%). It seemed that there was less traffic in the after situation, at least on the A15 motorway, but also (surprisingly) on the secondary road network. It could not be determined whether the decrease in vehicle hours delay was caused by the scenarios or by other circumstances. Variation between the analysed days was considerable, thus the difference between before and after situation was not significant. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

17 TRAFFIC FLOW ON A15 AND SECONDARY ROADS At network level no clear shift was found of traffic from the A15 motorway to the secondary road network. This paragraph describes the trajectory speeds and travel times on the A15 and congestion rate from day to day, and the shift in flow of traffic on the secondary roads. Only regular days were analysed. Flow of traffic on A15 motorway Trajectory speeds and travel times Table 5.5 shows the results of calculations with MoniGraph of the travel times and trajectory speeds for the sections on the A15 with corresponding connections. Connection indicator before after difference Route 05 and 06 Trajectory speed (km/h) % Travel time (sec) % Route 08, 09 and 10 Trajectory speed (km/h) % Travel time (sec) % Route 15 and 16 Trajectory speed (km/h) % Travel time (sec) % Table 5.5 Trajectory speeds and travel times on distinguished sections of the A15 During the morning peak the average trajectory speed did change hardly and during the evening peak the differences were higher: at some sections speed the change was more than 4%. On routes 05 and 06, trajectory speed and travel time changed only to a minimal extend. On the connection R08, R09 and R10 the average speed during the evening peak reduced to 30 km/h (Figure 5.1, left, blue=before, red=after). Speed was more stable in the after situation, but at the beginning and end of the congestion peak lower. During activation of the scenario, with VMS s displaying directive information for 1.5 hours (16:00-17:30), trajectory speed on the A15 was higher than in the before situation. No explanation was given for the change in travel time between before and after situation. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

18 Figure 5.1 Trajectory speed and travel time on the section of the A15 connected to routes 08, 09 and 10 Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

19 In the connection with R15 and R16, trajectory speed was also more stable in the after situation: clearly higher during, but lower at the end of the congestion peak (Figure 5.2, left, blue=before, red=after). No explanation was given for this more stable speed progress over time. During part of the activation of the scenario, with VMS s displaying directive information for 1.5 hours (16:15-17:45), traffic flow on the A15 was better than in the before situation: higher speed and lower travel time. Figure 5.2 Trajectory speed and travel time on the section of the A15 connected to routes 15 and 16 Vehicle hours delay and congestion rate Routes 05 and 06 On the part of the A15 where routes 05 and 06 are in parallel, the morning peak showed congestion on a regular basis. This resulted in 100 up to 150 vehicle hours delay on an average day, and 200 on busy days. The accompanying congestion rate was about 25 kilometres minutes on an average workday and up to more than 150 on busy days. See figure 5.3 for the day-to-day measurements during the 6 weeks analysis period. The mean value for vehicle hours delay was about 165 in the before and 135 in the after situation. For the average congestion rate these figures were respectively 28 and 19 kilometres minutes. The variation of both vehicle hours delay and congestion rate appeared to be higher in the after situation. after before after before after before Figure 5.3 Vehicle hours delay (blue) and congestion rate (red) on A15 for connection routes 05 and 06 Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

20 Routes 08, 09 and 10 On the A15 motorway, parallel to the alternative routes R08, R09 and R10, the number of vehicle hours delay was about 500 on an average day and was more than 2,500 on a busy day. Figure 5.4 shows the speed-contour plot of this A15 section for an average day and a busy day (source: MoniGraph, see Annex). The bottleneck, the Botlek tunnel, can be seen clearly on top of the image (the colours represent the average speed in km/h at a certain time and at a certain location on this A15 section). Figure 5.5 shows the values of this indicator and the congestion rate for the analysed days. The mean value for vehicle hours delay was about 500 both in the before and after situation. For the average congestion rate this figure was about 325, also for both before and after situation. The variation of both indicators appeared to be higher in the after situation with higher maximum values. Figure 5.4 Speed-contour plot of a normal and a busy day on a A15 section connected to routes 08, 09, 10 after before after before after before Figure 5.5 Vehicle hours delay (blue) and congestion rate (red) on A15 for connection routes 08, 09 and 10 Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

21 Routes 15 and 16 On the A15 parallel to alternative routes 15 and 16 the average number of vehicle hours delay was more than 1,000 and on busy days more than 2,000 on the analysed days. The averages for the congestion rate were kilometres minutes on a normal day and about 1,200 on a busy day. See figure 5.6. The mean value for vehicle hours delay was 1,300 hours in the before, and 1,200 hours in the after situation. For congestion rate these values were respectively 680 and 600 vehicle kilometres. The most extreme values for both of these indicators were seen in the before situation. after before after before after before Figure 5.6 Vehicle hours delay (blue) and congestion rate (red) on A15 for connection routes 15 and 16 Flow of traffic on secondary road network The traffic volumes on the secondary road network in before and after situation were analysed in order to get indications of the change in flow of traffic on the alternative routes. On the basis of the values of the 15 measuring points no unambiguous image of the change of traffic flow was possible. The secondary road network was expected to process more traffic, but this was not confirmed by the data. Rate of traffic volumes Botlek tunnel and Botlek bridge For crossing the river Oude Maas by car, two possibilities exist close to each other: Botlek tunnel and Botlek bridge. These water crossings are suitable locations to observe the route distribution as car traffic comes together here. Morning peak Figure 5.7 shows the development of traffic volumes at Botlek tunnel (before=blue, after=red) and Botlek bridge (before=green, after=yellow) during the morning peak in western direction (harbour-in). Between before and after situation, no clear differences in traffic volumes can be seen at the Botlek tunnel. Traffic volumes at the Botlek bridge were clearly higher in the before situation and congestion continued for a shorter period than in the Botlek tunnel. The Botlek bridge on the secondary road network is the alternative route for the Botlek tunnel in the A15 motorway. No shift from Botlek tunnel to Botlek bridge route could not be demonstrated due to activating the harbour-in scenario: traffic volume decreased at the Botlek bridge in the after situation while an increase was expected. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

22 Figure 5.7 Traffic volumes at Botlek tunnel and Botlek bridge in the morning peak Evening peak Figure 5.8 shows the development of traffic volumes at the Botlek tunnel (before=blue, after=red) and Botlek bridge (before=green, after=yellow) during the evening peak in eastern direction (harbour-out). Traffic volume in the Botlek tunnel in the A15 motorway appeared to be higher in the after situation scenario than in the before situation between 16:15 and 17:15. At the Botlek bridge traffic volume was lower in the same period of time although the scenario was then activated. Here the opposite happened of what was expected. Figure 5.8 Traffic volumes at Botlek tunnel and Botlek bridge in the evening peak Conclusions for traffic flow at route level Similar to the analysis of the network performance, no clear differences could be demonstrated between before and after situation in the detailed analysis of traffic flow per route. The median values of vehicle hours delay and congestion rate were a bit lower in the after situation, but the variation was high for both the before and after situation. The difference was therefore not significant. The course of the speed on the A15 was slightly lower and more stable than in the before situation. Only on one section of the A15 travel time clearly decreased during the evening peak (by more than 4%). This Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

23 was not due to the scenarios, because the number of vehicle kilometres and traffic volumes on the secondary road network decreased clearly as well. The total number of vehicle hours delay per analysed period was highly influenced by specific days with congestion although the mean values of vehicle hours delay in before and after situation did not change much (in after situation slightly lower). A clear shift in traffic flow from the A15 motorway to the secondary road network during activation of the scenarios could not be demonstrated. Moreover, the opposite seemed to occur ROUTE CHOICE EFFECTS In the harbour area, several VMS s were used for the traffic management scenarios. Five of these VMS s were analysed on their contribution to a shift in route choice. Figure 5.9 gives an overview of the locations of these five VMS s Figure 5.9 Overview locations of analysed VMS s The effect of the scenarios was analysed for regular situations (normal workday traffic) and non-regular situations (traffic accidents, road closures, etc.). For both situations, turning percentages of before and after situation were compared. Also the points in time were compared: the turning percentages in the quarter of an hour before and after activation of the scenario, and those before and after deactivation. The analysis of the non-regular days was performed for specific days with severe congestion, like major traffic accidents. Route choice effects in regular situations The VMS s were used for distributing traffic on the available road network. Downstream of the VMS s the effects in route choice were analysed. Table 5.6 presents the average turning percentages in the direction of the alternative route for the analysed 5 VMS s. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

24 VMS Route before after difference 1 A15L A15 > Gaderingviaduct 17.1% 17.4% +0.3% 2 A4R A4 > Gaderingviaduct 30.8% 32.0% +1.2% 3 Spijk Gr Kruisweg N493 > N % 18.1% 0.0% 4 R dam Botlekweg Botlekweg > Botlekweg 18.2% 17.4% -0.8% 5 N15R N15 > N % 20.4% +0.8% Table 5.6 Turning percentages of the analysed 5 VMS s None of these VMS s were able to cause a clear change in distribution of traffic due to the scenarios. On some of the analysed days they did, but on other days the effect was the opposite of what was expected. For the graphs of turning percentages: see next section (route choice effects in non-regular situations). Route choice effects in non-regular situations In non-regular situations with unusual traffic patterns, the expected effect of the VMS s during the scenarios was higher. The effects were analysed for extreme congestion during 4 workdays. VMS 1, morning peak During the morning peak of 19 June 2012, the Botlektunnel was closed starting at 7:00 with extreme congestion as a consequence. This lead to a clear shift towards the alternative route due to the information displayed on VMS 1. Figure 5.10 shows the turning percentages of the regular days (before=blue, after=red) for this VMS including the values for this specific day when the scenario was activated. Figure 5.10 Turning percentages VMS 1 (regular days and one non-regular day) A major change in turning percentages was found directly when the harbour-in scenario came in. At 8:15 the tunnel was opened again partially. The scenario seemed to be quite effective for days with severe congestion. VMS 2, morning peak Two lanes of the Botlek tunnel were closed on 5 June VMS 2 directed traffic to the alternative route via the Gadering viaduct. Figure 5.11 shows the turning percentages of the regular days (before=blue, after=red) for this VMS including the values for this specific day when the scenario was activated. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

25 Figure 5.11 Turning percentages VMS 2 (regular days and one non-regular day) The VMS displayed directive information from 6:20 till 7:44, first with a congestion icon and after 7:23 an accident icon. Exactly in this period a clear change in turning percentage was seen. Road users seemed to react in a different way on an accident icon than on a congestion icon. VMS 3, morning peak During the morning peak of 24 May 2012, an accident happened on a direct access road towards the A15. VMS 3 displayed information about an accident for 20 minutes. Figure 5.10 shows the turning percentages of the regular days (before=blue, after=red) for this VMS including the values for this specific day when the scenario was activated. The effect of the scenario was clear: a turning percentage towards the alternative route that was twice as high as during regular workdays. Figure 5.12 Turning percentages VMS 3 (regular days and one non-regular day) VMS 4 and VMS 5, evening peak Congestion was rather high during the evening peak of 21 June 2012 due to rainy weather and an accident near the Botlek tunnel. VMS 4 advised road users to follow the alternative route already at the beginning of the evening peak. VMS 5 displayed route information between 15:30 and 16:25, advising road users to Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

26 follow the alternative route N57-N218 instead of the A15 motorway in eastern direction. The result was a major change in turning percentage around 16:30, much higher than during regular days. Figures 5.13 and 5.14 show the turning percentages of the regular days (before=blue, after=red) for this VMS including the values for this specific day when the scenario was activated. Figure 5.13 Turning percentages VMS 4 (regular days and one non-regular day) Figure 5.14 Turning percentages VMS 5 (regular days and one non-regular day) Conclusions route choice effects With normal traffic flows, the effect of directive route information on VMS s was limited and not significant. VMS s had no effect on route choice as the given information only confirmed their assumptions. In non-regular situations (such as accidents or partial road closures) the effect was very clear. When road users were informed about an accident or capacity restriction, considerable shifts in route choice were noticed, as expected OVERALL CONCLUSIONS The traffic management scenarios harbour-in and harbour-out should have caused a shift of traffic flow from the A15 motorway to the secondary road network by using traffic management measures like directive Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

27 information on VMS s and adjusted traffic lights. However, this effect for normal workdays could not be demonstrated through the evaluation study. Although the evaluation period of 6 weeks was rather short, and the resulting number of suitable workdays limited, unambiguous conclusions were not possible. The overall effects of the activated traffic management scenarios were limited and not significant for regular workdays. The effect of the scenarios was, however, very clear for non-regular workdays with more than normal congestion due to accidents, weather circumstances etc.: major changes in turning percentages of traffic on the secondary road network. Normally road users would follow the A15 but, as a result of the information on the VMS s about the severity of the situation, they kept following the (alternative) secondary roads Reliability of Results In order to get reliable answers for the research questions, efforts were done in this ex-post evaluation study to reduce or even exclude (external) sources of bias, like changes in traffic volume due to economic effects. More specific: The evaluation period was short, but the before and after measurements were done in an alternate way: one week of after situation followed by one week of before situation and so on, all within a 6 weeks period. The results for the A15 motorway were more reliable than for the secondary road network. The amount of available data for the A15 was more than sufficient. The available data for the secondary roads was more limited, thus leading to a rather qualitative judgement of the effects on these roads. As a result of calculations of significance through statistical checks, the determined changes in traffic flow on the A15 motorway could be regarded as highly reliable for this evaluation study Research Questions Answered See section Overall Assessment Below the main finding of the evaluation are summarised in brief in terms of contribution to the European objectives SAFETY Not evaluated EFFICIENCY Traffic flow on the A15 motorway changed hardly due to the traffic management scenarios and the determined effects did not appear to be significant. Only in non-regular situations (with more than normal congestion on the A15) the secondary roads were followed for a longer time than on normal workdays with regular traffic patterns. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

28 ENVIRONMENT Not evaluated and it was difficult to draw conclusions on this item, given the fact that the overall effects were not significant. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

29 6. European Dimension: Transferability of the Results The following conclusion can be made regarding the applicability of the results of this project to other similar implementations in the Netherlands and other countries: The deployment of traffic management scenarios, using basically already installed roadside equipment in the study area, could be profitable for urban and industrial areas in order to achieve a better throughput of the traffic in specific areas around these areas. This is especially the case at peak hours with non-regular traffic flows due to accidents, adverse weather situations etc. Development of traffic management scenarios should be done on a tailor-made basis: all road networks are different and require specific configurations, trigger values and threshold values. Solid traffic monitoring tools and loggings proved to be the vital factor for a constant improvement of the traffic management processes including traffic scenarios. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

30 Annex 1: MoniGraph MoniGraph is a tool to process, analyse and visualise data from the Rijkswaterstaat loop detectors. It was developed and is still maintained by Henk Taale. In the two figures below, an example is presented for the visual output of MoniGraph. With this tool it is possible to produce a graphical representation of the traffic speeds in a certain time period. In the examples, the traffic situation on the entire A10 Ring road can be observed, from the Coentunnel in the north of the A10 (at the bottom of the graph) via the outer ring (anti-clockwise) back to the same tunnel. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013

31 The first graph shows a before situation, the second an after situation. Per graph, three typical afternoon peaks were selected of specific days with low, medium and high traffic volumes. The graphs show the measured speeds as a function of time and space. All input for these graphs came from the loop detectors on the A10 motorway. Traffic Management Scenarios on the A15 Motorway (Rotterdam) August 27 th, 2013