Friday, April 5, 2019
The delft network in the netherlands
The delft ne twainrk in the netherlands1 About the Delft internetDelft is a metropolis located in the Netherlands, having a population of 96168. It is spread over an ara of 24 sq.km. (Wikipedia 2009a). The Delft University of Technology is the largest proficient university in the Netherlands, with over 15,000 students (Wikipedia 2009b). Due to the signifi stinkert student population, cycling is an important system of transport.Delft is bound by freeways on all berths, except the southern, which is delimited by a highway. The hierarchy of roads in Delft is freeways, highways, first-string(prenominal) roads, and local roads. The racecourseway line cuts across the city, running in the north-south direction from the centre of the city. A master(prenominal) road and a highway are the principal(prenominal) linkages between the two freeways on the either side of the line line.2 Transport Problem in DelftThe railway line passing through Delft is a comp integritynt of 1 of the pri ncipal railway connections in the Netherlands, connecting Rotterdam and The Hague. The existing 2-track railway line is insufficient, and it has been planned to be upgraded to a 4-track line. However, due to lack of station to build another viaduct, and environmental problems cause by the railway line, it has been proposed to restore the railway line in a tunnel. 2020 is envisaged to be a typical year while the verbal expression is in operation. Thus, link ups 10486, 9873, and 9827 testament be obturate for all handicraft. Due to the detours which would result due to the blocked links, cyclists and elevator cars would grant to deal with increased travel quantifys. It is anticipated that Mercuriusweg/Abtwoudse Pad or the Ruys de Berenbrouckstraat links would be used in lieu of the blocked links (Chen 2009).3 Description of flow rate scenario and Alternate Scenarios3.1 Description of the Current Situation 2003 regularises 1-7 are the extraneous partitions, whereas the res t of the regularizes are considered as the internal zones. The internal zones are the primary areas of concern. It has as well as been given over that in 2003, zones 23, 24, and 25 are still under development and there is no travel demand from and to these zones (Chen 2009).3.2 Description of the Zero-Alternative Situation 2020By 2020, zones 24 and 25 will maintain been wholly developed. However, partition 23 would still not induce been developed. Infrastructure has been upgraded accordingly to connect zones 24 and 25 with the rest of the city. Zone 12 dust the highest unhorse generating and trip attracting internal zone, as does Zone 1 amongst the external zones.3.3 Description of Future Situation during Construction 2020Considering the future scenario for the city of Delft in 2020 during the expansion of the rail line from 2-track to 4-track, it shall be assumed that this project will be in progress and 2020 will be a typical year. It has been given that during the expan sion, connect 10486, 9873, and 9827 will be blocked (Chen 2009). The trip generation remains the same as for the zero-alternate scenario for 2020.4 Modelling for Current Situation 20034.1 trip up GenerationFor performing the trip generation mouldling incline, the Zonal-based Multiple Regression model has been employed. It takes into account the linear relationships of the socio-economic characteristics of the households in the zones, which affects the trips produced and attracted for each zone (Ortzar and Willumsen 1999).The following functions have been used for the trip generating model in the case of internal zonesPi = 0.3RESIDENTSi + 0.06JOBSi + 0.03RESEARCHi + 0.03EDUCATIONiAi = 0.05RESIDENTSi + 0.75JOBSi + 0.3RESEARCHi + 0.3EDUCATIONiWherePi = production of zone i,Ai = attraction of zone i,RESIDENTSi = frame of residents in zone i,JOBSi = do of jobs in zone i,RESEARCHi = research facility space in zone i,EDUCATIONi = amount of educational serve offered in zone i.Source Chen 2009For the case of external zones, the heels of trips generated and attracted have been assessed based on the dealings volume counts. These are as indicated in Appendix 1.For the internal zones, it screw be seen that the inconstant of the number of residents living in each zone is the most dominant one affecting the number of trips produced. The variables which are most dominant for trip attraction are number of jobs, and the research facility space in that particular zone respectively.Appendix 2 indicates the trip generation for 2003, including both the internal as considerably as the external zones.2003 histogram.JPGFigure 4-1 Productions and Attractions for the Current Scenario 2003It go off be seen from the Appendix 2 and figure 4-1, Zone 12 is the largest trip generator and attracting external zone. Zone 1 is the highest trip generating and attracting internal zone.4.2 hinge on dissemination and Modal SplitThe Gravity Model has been employed to generate the trip di stribution model. This model is a type of Synthetic Model as it estimates trips for each cell in the matrix without outright employ the ascertained trip pattern (Ortzar and Willumsen 1999 p.159). There are three variants for the Gravity Model function, namelyexponential function make f(cij) = exp (-cij)Power Function f(cij) = cij-nCombined Function cnij exp(-cij)Singly constrained versions, in this case destination-constrained, can be produced by making Ai equal to 1, i.e.Ai = 1 and Bj= 1/?iDif(cij)The Combined Function variation of the Gravity Model is the most superior one, as it is the best fit with the actual observed values for trip length distributions of cars (Ortzar and Willumsen 1999). OmniTRANS performs simultaneous modal split, for which the gravity model can be protracted to the simultaneous gravity model which is given byTijv=p.Qi.Xj.Fv(zijv)WhereTijv= Number of trips from zone I to j via mode vp= Scaling factorXj= Column Balancing FactorFv(zijv)= Distribution funct ion taking into account the willingness to travel by mode v given impedance zAppendix 4 indicates the traffic distribution of cars in Delft. 44566 cars have been distributed. As can be seen in Appendix 5, 8635 cyclists have been distributed the entire network of Delft.The modal split indicates that 83.77 per centum of the traffic is constituted by cars and 16.23 part by motorcycles.The trip length distribution function for cars can be seen in figure 4-2. This indicates the willingness to travel to a certain hold without any impendence, such as congestion. Hence, in this case the level best uncongested remoteness travelled is 10 km. Similarly, figure 4-3 indicates the trip length distribution for oscillations, which experiences its peak at 3 km.The trip time distributions for cars and bicycles have been indicated in Figure 4-4 and Figure 4-5 respectively. These functions, too, follow a similar pattern as that of the actuate Length Distribution. In the case of cars and bicycl es, both, the peak is of 12 minutes.The call back trip distance for bicycles is 3.14 km and the mean(a) trip time is 14.22 minutes. Similarly, for cars, the mean distance is 7.59 km and time is 11.12 minutes.Intra-zonal car trips constitute only intimately 0.57 pct of the total number of trips made by cars, and those made by bicycles constitute roughly 16.55 percent of the total number of bicycle trips.4.3 art assignment4.3.1.1 Assignment for CarsThe General Equilibrium technique of traffic assignment has been used for cars. The condition as given by Wardrop is that Under equilibrium conditions, traffic arranges itself in congested networks in such a way that no individual trip maker can reduce his path cost by switching routes (Ortzar and Willumsen 1999 p.303). Under this traffic assignment model, costs are all perceived in the same way by the trip makers, and hence random effects are not considered.The following links have the largest traffic flow (for a single direction) of more or less 7064 cars assigned 10972, 10973, 11289, 11427, 11428, and 11477. Figure 4-6 represents the traffic assignment for cars in 2003. The colours of the bands, in the graph, indicate the V/C Ratio and the width indicates the traffic load. It reflects that the main road, the east and west freeways crossing the railway are twinge from V/C ratios greater than 1, which requires attention.4.3.1.2 Assignment for BicyclesThe Stochastic Method has been employed for the traffic assignment model for bicycles. This method is superior to the All-Or-Nothing Method, as it takes into account the diversity in the road users perceptions of distance, travel time, generalised costs and thus considers alternate routes to the best-route choice, given by the All-Or-Nothing technique. This is a suitable model for the traffic assignment of bicycles as this technique does not take into account the congestion effects, which is not calculable since capacities for bicycles are not specified.Link 10 850 has been assigned the maximum number of bicycle trips for a single direction, which is 941 trips. Figure 4-7 represents the assignment of bicycles in 2003. or so of the trips are confined to the internal zones.5 Modelling for Future Situation 2020The modelling stages for the future scenarios of 2020 will remain the same till the trade Assignment Stage, which would differ based on the blocked links for the future construction scenario of 2020.5.1 Trip GenerationThe Zonal-based Multiple Regression model has been employed. The functions are the same as those for 2003. However, forecasts for the number of residents, jobs, and the research facility space and education building space in 2020 are disparate from the current year. Also, it has been given that the productions and attractions generated by the external zones is to be assumed to grow by 15 percent from 2020 to 2003 (Chen 2009).The above figure 5-1 illustrates that Zone 1 still remains the highest trip production and attra ction external zone and Zone 12 continues to remain the highest trip producing and attracting internal zone. The same is reflected through Appendix 3.5.2 Trip Distribution and Modal SplitThe Gravity Model has been employed for the trip distribution. A total of close 54380 cars have been distributed, and about 10413 bicycles. The modal split for 2020 demonstrates that about 83.5 percent of the trips would be by cars, and the remaining 16.5 percent by bicycles. For cars, the intra-zonal trips constitute about 0.54 percent, whereas for the bicycles, intra-zonal trips constitute about 15.71 percent of the trips.Trip length distribution function (indicated in Figure 5-2 and 5-3) and the trip time distribution functions (indicated in Figure 5-4 and 5-5) have been generated. The maximum uncongested distance remains the same for both cars and bicycles, as in 2003, as also the maximum uncongested time in the case for cars. For bicycles, the maximum time has reduced to 8 minutes.The mean tri p distance for bicycles is 3.26 km and the mean time is 14.75 minutes. Similarly, for cars, the mean distance is 7.56 km and time is 11 minutes.5.3 Traffic Assignment for Zero-Alternative Situation5.3.1 Traffic Assignment for CarsThe General Equilibrium model has been employed. The following links have the maximum numbers of cars assigned, i.e. about 8346 cars, to them for one direction Links 10972, 10973, 11289, 11427, 11428, 11477, and 11478. Figure 5-6 represents the assignment for cars. The colours of the bands, in the graph, indicate the V/C Ratio and the width indicates the load of traffic. The freeways continue to have high V/C ratios, as well as the main roads crossing the railway.5.3.2 Traffic Assignment for BicyclesFor the traffic assignment modelling for bicycles, the Stochastic Method has been used again. Link 10850 has been assigned the maximum number of bicycle trips (114 trips). Figure 5-7 represents the bicycle assignment.5.4 Traffic Assignment for Future Constructio n SituationIn the future situation during construction, the decision to upgrade the railways from two tracks to four tracks has been made. This would result in the closing of Links 9827, 9873, and 10486.5.4.1 Traffic Assignment for CarsIt has been calculated that links 11283, 11407, 11463, and 11464 have the maximum load, of 10723 cars in one direction. Figure 5-8 represents the car assignment considering future construction. The cross-railway link south of zone 17 experiences a greater load, whereby there is a reduction in the northern cross-link.5.4.2 Traffic Assignment for BicyclesThe Stochastic model employed for assigning the bicycle traffic that Link 10452 the maximum load, in one direction, of 1446.54 bicycles. Figure 5-9 represents the assignment for bicycles.6 Analysis6.1 Trip GenerationAmongst the internal zones, which are of primary concern, Zone 12 is the zone which remains the highest trip producing and attracting zone. This is supported by the fact that Zone 12 has the highest number of residents living in it, and the maximum number of jobs existing in this zone. This zone is located at the watch of the city, adjacent to the railway line and the main road connecting the two freeways. All the internal zones have see a growth rate for the number of trips generated and produced by about 11 percent.Zone 1 also remains the highest trip producing and attracting external zone. This whitethorn be accounted by the fact that Zone 1 is directly connected to Delft by the railway line, and thus could perhaps be an important junction or location.6.2 Trip Distribution and Modal SplitThe trip distribution can be reflected through the study of the matrices given in Appendix 4 to 7. For 2003, the maximum number of car trips has been of the nature Internal-to-External, with the most dominant one organism from Zone 15 to Zone 1. This has not changed for 2020. For 2003 and 2020, the most dominant character of bicycle trips is Internal-to-Internal, with maximum trip s being made within Zone 12. This is as should be expected, since long distance travel by bicycles is not likely to be made except in rare circumstances. The maximum number of bicycle trips may also be attributed to the fact that Zone 12 is the Delft City Centre. The maximum growth (4.8 times) for car trips has been seen for the pair Zone 7-Zone 1, and the maximum for bicycles (0.15 times) has been for the pair Zone 5-Zone 12.On studying the zone-to-zone average travel distance and time, it can be seen from Appendix 8 and 9 that the maximum increase for trip distance has been from zone 7 to 15 (46.86 percent) and maximum increase in time has been for the pair zone 18 to 22 (48.67 percent). The maximum increase (48.78 percent) in cost has been experient for zone 11 to 22.The modal split indicates a marginal change from 2003 to 2005, whereby there is a step-down from approximately 83.77 to 83.5 percent for cars. Intra-zonal trips made in 2020 have experienced a fall from 2003. This may indicate greater travel distances and time, and thus greater reason costs in the future.6.3 Traffic AssignmentOn comparing the figures indicating the traffic assignments for the three scenarios, it can be seen that the maximum car trips load remains on the freeways defining Delft on the eastern and western sides. The main difference can be seen between the zero-alternative and construction situation for 2020.Due to the blocked links, car traffic has been assigned to the links 1164, 11645, and westernvest-Hooikade particularly have experienced a significant increase, whereas the Westlandseweg links have experienced a decrease in the load of trips. Also, as was expected, there was an increased use of the Ruys-de-Berenbrouckstraat, and Abtwoudse links. However, the Mercuriusweg saw a decrease in the traffic load as compared to the zero-alternative scenario, which goes against as was anticipated. In the case of assigned bicycle trips, due to the blocked links, the Hof-van-Delftlaa n link has seen a substantial increase in the traffic load.The share of the railway crossing traffic has been seen to change for all the three scenarios. This has been indicated in figure 6-1. There is a decrease in the share from 2003 to the Zero-Alternative scenario. However, comparing the future construction scenario with the Zero-Alternative, there has been an increase in the share, for both cars and bicycles.7 ConclusionsZones 1 and 12 being of prime importance, also supported by their connectivity will continue to get over as the zones attracting and generating the maximum traffic. Since maximum bicycle traffic load is concentrated in Zone 12, measures may be taken to restrict the entry of cars in this area so as to ensure a more safe environment, which would even benefit the households, as the maximum percentage are located in this zone. Increased generalised costs must be taken into account, based on the above analysis. Links which are experiencing greater traffic loads due to construction works have been identified, and relief measures for these should be planned, particularly for the freeways on the eastern and western side of the city.8 Strengths and Weaknesses of OmniTRANSThe strength of OmniTRANS is that it helps in the rapid and hi-fi transport modeling procedures. Also, the data can be very easily examined on the transport network map, rather than just being confined to tables and numbers, which makes analysis tedious. Also, a number of variables can be studied, which can be further sorted out based on the direction for any particular link.The weaknesses could be cited as only being able to employ the use of the Simultaneous Gravity Model being available for trip distribution stage. Also, only limited types of traffic assignment models can be performed (such as Stochastic, All-or-Nothing, and Equilibrium). Public transport modelling is also not performed by the software (OmniTRANS 2009).ReferencesCHEN, H. 2009. Handout Coursework Description, lecture notes distributed in TRAN5020 Principles of Transport Modelling. University of Leeds, 3 November 2009.OMNITRANS. 2009. Whats New in OT5 online. Accessed on 1st December 2009. Available from http//www.omnitrans-international.com/resources/brochures/whats%20new%202008.pdf.ORTZAR, J. WILLUMSEN, L.G. 1999. Modelling Transport. West Sussex Wiley.WIKIPEDIA. 2009a. Delft online. Accessed on 10 November 2009. Available from http//en.wikipedia.org/wiki/Delft.WIKIPEDIA. 2009b. Delft University of Technology online. Accessed on 10 November 2009. Available from http//en.wikipedia.org/wiki/Delft_University_of_Technology.
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment