Instructions
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1. Cost Analysis and ADT Calculation We will not conduct any cost or ADT calculations within this exercise thus unmark the two alternatives Calculations Cost Analysis and Calculations ADT Calculation Geometry input The appearance of the tab Geometry overview varies depending on which intersection type that is chosen in the drop down list up to the left The tab has one appearance for stop one for yield one for signal and one for roundabouts Figure 2 shows the different data that can be edited for each approach The allowed turnings are edited by clicking with the right mouse button on the picture that shows the allowed turnings The gradient is the vertical incline of the current approach Geometry B E D Stop line Radius AT 12 12 12 Angle 90 390 30 Gradient o o oO Exit lane width Allowed turnings Shoulder width Refuge width P umber of lanes AB D Lane width One lane 2 5 8 0 m two or more lanes 2 5 5 5 1 Remove Add the current Remove Add the intersection exit current approach Figure 2 Geometry input to CAPCAL Some of the input data is illustrated in Figure 3 S Distance to stop line Exit width Figure 3 Illustration of some of the geometric input data Source Capcal User manual Figure 4 and Figure 5 illustrate some additional geometric input data for roundabouts Sen l length of merging area b width of merging area Figure 4 Illustrat2. 281 Straight on 513 748 460 644 Right 393 578 175 245 Total 1164 1698 836 1170 Pedestrians 43 57 45 60 S Left 9 13 13 18 Straight on 118 164 99 139 Right 181 255 318 445 Total 308 432 430 602 Pedestrians 101 129 73 100 Total 2150 3078 2450 3430 Table 5 Traffic volumes for Tornavdgen Dalbyvdgen peek hour Heavy vehicle share 3 12 Flow vehicles h Morning Afternoon Approach Turning Today Forecast Today Forecast W Left 167 225 102 147 Straight on 446 599 1054 1520 Right 571 767 317 458 Total 1184 1591 1473 2125 N Left 4 6 3 4 Straight on 29 39 24 34 Right 138 185 157 227 Total 171 230 184 265 E Left 127 171 58 83 Straight on 1136 1527 640 923 Right 2 3 7 10 Total 1266 1701 704 1016 S Left 224 301 451 650 Straight on 28 38 24 34 Right 31 42 143 206 Total 283 381 617 890 Total 2904 3903 2978 4296 Table 6 Traffic volumes for Porfyrv gen Dalbyv gen peek hour Heavy vehicle share 3 13 Flow vehicles h Morning Afternoon Approach Turning Today Forecast Today Forecast W Left 180 647 467 252 Straight on 276 1001 7133 386 Right 50 22 18 70 Total 506 1670 1218 708 N Left 26 113 82 36 Straight on 113 63 50 158 Right 527 378 275 738 Total 666 554 407 932 E Left 46 21 18 69 Straight on 769 372 282 1035 Right 73 20 14 102 Total 888 413 314 1206 S Left 23 101 73 32 Straight on 39 136 97 55 Right 17 113 81 24 Total 79 350 251 111 Total 2139 2987 2190 2957 Table 7 Traffic volumes for Albyvdgen Sandbyvdg
3. 4 s example 2 and 5 s example 3 Do not take the short lanes into considerations The phase configurations is explained below and in illustrated in appendix 7 Example 1 Mixed phase 2 phase Example 2 Phase all turnings from west and east Phase 2 all turnings from east Phase 3 all turnings from north and south Example 3 Phase 1 right and straight turnings from west and east Phase 2 all turnings from north and south Phase 3 left turnings from west and east Phase 4 all turnings from west Calculate the different intersections Do the intersections work sati factionary If the degree of saturation exceeds 0 7 for any of the intersections try to modify the intersections or the signal timing so that degree of saturation gets below 0 7 Which methods did you test and which of them worked Redo the calculations for example 1 and 2 but now with the length restrictions for the short lanes Do the results change noticeable 10 How to choose intersection type The Swedish road administration has developed a rough calculation method that can be used to give indications on which intersection type that is suitable see Figure 6 Use the method to check which intersection type that is suitable for the 7 different intersections in Table 4 Choose Intersection type god good smaller intersection type mindre god moderate consider larger intersection type black marked area larger intersection type
4. A B C D Left Straig Right Left Straig Right Left Straig Right Left Straig Right ht on ht on Table 4 Traffic volumes for 7 different intersections Qs bjDh Olamplig B 600 trafikFor sef delning j A for mindre i i korsning A xs o C 00 Qp b Dh 0 500 1000 1500 Figure 6 Rough calculation method for control of degree of saturation during the dimension hour for an urban intersection figur 7 5 2 2 VR50 for fyrv gskorsning ur VU 94 Calculate the degree of saturation with Capcal for one or more of the intersections Grade the quality of service and compare it to the VU94 method is the answer the same 11 Calculations of Dalbyvagen in Lund Appendix 8 shows an overview of the south east parts of the Swedish city Lund There are four main intersections in the overview picture Dalbyvagen Tornavagen Dalbyvagen E22 Dalbyvagen Porfyrvagen and Albyvagen Sandbyvagen Signal phase schemes are available in appendix 9 12 i e signal controllers 46 912 15 and 941 Traffic volumes are found in Table 5 to Table 7 flows for Dalbyva gen E22 is missing Flow vehicles h Morning Afternoon Approach Turning Today Forecast Today Forecast W Left 34 49 52 73 Straight on 303 423 656 918 Right 8 11 28 39 Total 345 483 736 1030 Pedestrians 20 30 13 15 N Left 205 281 317 444 Straight on 110 162 99 139 Right 18 22 32 45 Total 333 465 448 628 Pedestrians 143 189 196 223 E Left 258 372 201
5. LINKOPINGS TEKNISKA HOGSKOLA Traffic signals 2007 ITN Johan Janson Olstam TNK062 Traffic modeling 2007 11 23 Computer exercise with Capcal Introduction This computer exercise is an introduction to the calculation program Capcal 3 Capcal CAPacity CALculation is a computer program for calculating effects of intersections and roundabouts In this exercise you will practice calculations of non signal intersection signal intersections and roundabouts For some of the tasks will blueprints from VU 94 Road design 94 be used these blueprints is available in the appendix but not in digital form Except the guidance in this document there is also a program manual at c program capcal3 unfortunately only in Swedish and a help function which can be accessed via the Fl button on the keyboard The aim with this exercise is to increase your knowledge on different intersections types effects intersection performance The aim is also to increase the understanding of how different traffic signal strategies work and which effect they have on an intersection The examination in the traffic signal part in the course TNK062 Traffic modeling will include a small project with Capcal and the aim of this exercise is therefore also to give basic knowledge for running Capcal In this document will menu and tab choices be written in bold style for example perform calculation Calculation Intersection Input and calculation Start Capcal from the s
6. egulation to roundabout Redo the calculations and compare the results with the chosen intersection What are the differences Create a new intersection Use blueprint D 4g appendix 3 and feed the model with the necessary geometric data The B street have speed limit 50 km h while the other streets have 70 km h Use traffic volumes from Table 3 A B C D left straight right left straight right left straight right left Straight right 230 790 160 30 140 200 330 530 40 230 190 490 Table 3 Traffic volumes for a roundabout for the afternoon peek Heavy vehicle share equal to 10 and a pedestrian flow of 230 pedestrians h crossing the B street How high is the level of service for this intersection How long is the total interaction delay Change the geometry of the intersection to only one incoming lane per approach Redo the calculations and compare the results What differences can be observed Intersection type E Terms Open the standard intersection Eovra4 available from the Capcal program directory under typkorsning View the signal phases and signal groups from the Signal tab How many signal groups are there How many phases are there It is possible to edit the phases as one desire but with the restriction that primary conflicts is not allowed There are also some other restrictions Test to allow straight forward traffic in phase 2 by clicking on the arrow Conduct a calculation w
7. en peek hour Heavy vehicle share 3
8. hat happens Notice the information in the information field at the bottom of the Capcal window Thus it is not possible to conduct a calculation when the phase configuration is conflicts with the rules for signal groups which is the signal group rules Information about which conditions that is not fulfilled is given at the information field at the bottom of the program window Edit the phase pictures to the original set up Click with right mouse bottom on phase 2 and click on Edit in the pop list that appears It is now possible to edit the phase freely It is now possible to allow right turnings from approach D do so and then close the dialog box The phase now becomes grey which means that there exists a primary conflict However if it in this case is possible enough space etc to turn left from C and right from D at the same time there is no conflict Perform a calculation what happens Below follows an overview of some important traffic signal terms in Capcal Signal control Capcal calculates a fixed time signal i e the signal is not affected by the traffic in real time The signal control should be changed to Signal group control when modeling modern adaptive traffic signal Capcal then performs a correction of the results so that they better correspond to a modern traffic signal Cycle time The cycle time can be set by the user 30 200s or be set to be calculated by the program 40 120s If Capcal is se
9. hortcut on the start menu and program Capcal Input data to Capcal is prepared in the tabs Geometry overview Volumes and Signal There is also a tab for Report and Printout see Figure 1 gt Capcal 3 2 0 5 Noname ndrad Joey File Calculation Help Geometry overview Volumes Report and print Licensagare Inst for teknik och naturvetenskap Link pings Universitet Over view YI A 0 5 0 0 0 3 5 a 0Til 5 EA lt E sso Road 50 50 50 50 RT e Local 50 50 50 50 5 Geometry D Stop line Radius AT 12 12 12 12 Angle 30 90 930 90 Gradient 10 0 0 0 Yield East West North South z o I Crossing in two steps am 5 0 gt o asp gt HI 0 0 5 0 0 y D Intersection type type of control Figure I Screen picture from CAPCAL The data that should feed into Capcal varies depending on intersection type and which calculation that should be performed Non signal intersections for example only demand data under the Geometry and Volumes tab while signal intersections also demand input data under the Signal tab It is for each intersection type only possible to edit the data needed for the calculation of the specific intersection type Calculation settings Capcal can be used to conduct different kinds of calculations The type of calculation should be performed can be edited from the Calculations menu by marking or unmarking
10. ion of some of the geometric input data Source Capcal User manual The width of the merging area is no longer used in Capcal Instead the number of circulating lanes should be specified i e number of lanes in the roundabout and not the number of lanes in the approaches The length and the number of lanes in the roundabout are specified under the Header Roundabout see screen shot on next page lt gt Capcal 3 2 0 5 Noname ndrad Liles File Calculation Help Geometry overview Volumes Calculation variables Report and print Licensagare Inst for teknik och naturvetenskap Link pings Universitet Over view po v i A r 7 0 i 35 Speed Ae leo KE 350 Road 50 50 50 50 al al Local 50 50 50 50 Roundabout Length m E gt y p Al Intersection type type of control Figure 5 Illustration of geometric input data for roundabouts in Capcal Traffic input Each approach and turn relation has to be assigned a traffic volume vehicles h The proportion of trucks in percent is edited in the box besides the truck symbol The bicycle edit box refer to the number of bicycles cycles h driving among the vehicles in the lane thus not bicycles on separate tracks The pedestrian edit box refer to pedestrians and bicycles that cross the approach using an zebra crossing but only if the zebra crossing lies in connection with the intersection Change volume 0 4 Execu
11. r quality of service measures are delay and queue lengths Delay is probably the measure that most road users observe Delay is also the measure that is easiest to express in monetary terms Queue lengths are important for dimension of extra lanes in an intersection vehicle store possibilities and for controlling that the queues do not block intersections upstream Intersection type B What is characteristic for intersection type B Create a new intersection File New Use blueprint B 3gm appendix 1b feed the model with the necessary geometric data Choose yield regulation Add traffic volumes according to Table 1 Save the intersection conduct the calculation and view the results Are there any differences compared to intersection type A Why why not How high is the level of service for this intersection Intersection type C What is characteristic for intersection type C Create a new intersection Use blueprint C lg appendix 2 and feed the model with the necessary geometric data Choose yield regulation and add traffic volumes according to Table 1 Save the intersection conduct the calculation and view the results Are there any differences compared to intersection type A Why why not How high is the level of service for this intersection Intersection type D What is characteristic for intersection type D Choose any of the intersections model calculated above Change r
12. t to calculate the best cycle time all values between 40 and 120 s with intervals of 5 s is tested Safety time The safety time cannot be handled at signal group level The safe time must instead be set to the safe time that is dimensional for the phase Min green The min green time should be set to 4 or 6 seconds for motor vehicles normally 4 seconds at roads with speed limit 50 km h and 6 seconds at roads with speed limit 70 km h Min green time for pedestrians must be set so that they are able to cross the road during the min green time Max green The max green time should normally not be set A value of 0 means that the max time is unrestricted Start offset End offset Start and end offset time can be used when more than one signal group have right of way in a phase in order to model that the signal groups have different start and or end times It is normally only the safe and min green time that needs to set The calculations is not that exact that offset times has any large impact Capcal is not recommended for calculations of coordinated traffic signals since it cannot handle the effects of the coordination Capcal will give a higher delay than reasonable For coordinated systems one should use programs like TRANSYT Tasks Do calculations for example 1 3 from TV131 see appendix 4 7 Please observe that there is both morning and afternoon traffic volumes available for example 3 Use the following safe times 3 s example 1
13. te A Vehicle volume vehicle hour including heavy vehicles but without bikes Intersection type A Create a new intersection File New Choose yield regulation and set the speed limit both for the road and local to 50 km h Use geometric input data from blueprint A 3 gm appendix 1 make reasonable assumptions for data that is missing Change to the volumes tab and add traffic volumes according to Table 1 A B D left straight right left straight right left straight right left Straight right 340 120 29 40 45 70 Table 1 Vehicle volumes for exercises concerning intersection types A B and C Heavy vehicle share 10 and pedestrian and bicycle flow equal to 0 Save the intersection File Save Conduct calculations Calculation Intersection and view the results under the Report and Print tab It is possible to choose which input and output data that should be shown Change regulation to stop instead of yield Save the intersection with a new file name and redo the calculation Compare the results are there any differences If so what is the reason An alternative to start to prepare a Capcal intersection from scratch is to use one of the standard intersections available in the Capcal program directory under typkorsning Choose a standard intersection similar to A 3gm and feed the model with traffic volumes Calculate and compare the results with the earlier results Is there any differences Why wh
14. y not Note The results from Capcal depend on several variables Some of them have a large impact on the result for example the number of lanes while other has little impact for example the lane width Please experiment in order to find out which impact different variables have on the result Test for example to increase the number of lanes and the lane width at some other approach The two most used measures of quality of service are delay and degree of saturation Increase the traffic flow successively and study how delay and degree of saturation changes do the delay and degree of saturation have a positive or negative correlation What happens when the degree of saturation gets close to 1 The results are also saved in the file capout xls which is available in c program capcal3 Quality of service measurements The document VU 94 http www3 vv se vu94s2 include a quality of service measurement based on the degree of saturation see Table 2 The measure is defined per lane and refers to the lane with the highest degree of saturation Intersection type High standard Moderate standard Low standard ABCD lt 0 5 0 5 0 7 gt 0 7 E 0 5 0 7 0 3 0 5 0 7 0 8 lt 0 3 gt 0 8 Table 2 Quality of service measure based on degree of saturation according to VU 94 Grade the level of service for the A 3gm intersection and henceforth according to Table 2 How good is the quality of service Othe
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