Knowledge

Public transport accessibility level

Source πŸ“

330:). A new public transport network was recommended to improve PTAL in areas most likely to develop in the near future. The second application was to improve the zoning for transit-oriented development. The third application is aimed at making public transport more inclusive. The study found that the proposed public affordable housing projects are in areas with poor PTAL, which could hamper the occupancy in these projects; the slums, on the contrary, were in high-PTAL areas. Recommendations included proposing affordable housing projects in areas having high-PTAL. The fourth application explored was to enhance micro-level plans. An area of 1 km was assessed using 100 m grids. The PTAL analysis revealed which areas have poor PTAL. Improvement in the quality of pedestrian infrastructure and street connectivity was recommended; the new PTAL map, thus, generated demonstrated improved PT accessibility (see figure 517: 476: 174:) by Bhargav Adhvaryu and Jay Shah. PTAL mapping for other Indian cities if under progress. In the London method, points of interest (POIs) were considered by the actual development (e.g., buildings). However, in Ahmedabad, given the lack of availability of building footprint data at the time of the study, the method deviated by construing POIs as centroids of a 1 km grid. Given that the purpose of the study was to explore implications of PTAL at a macro-scale (i.e., development/ master plan level – the study area being 465 km) and the data constraints, the grid-cell approach seemed justified (comparison for which is discussed in the section on 231: 346:, a twin-city region that is one of fastest-growing cities in Karnataka State. The analysis was based on the methodology adopted for Ahmedabad and Surat, with new methodological innovations (explain below). The city follows a Master Plan 2031 Revision–II (made in 2017 and approved in 2019), which has opened new areas for development. This established the need to analyse the accessibility of the public transport network in relation to the planned future developments that builds on the analysis of the current situation. The mapping provides a visual representation of the existing accessibility levels (see figure 19: 313: 194:(a section of which started operation in March 2019). Lastly, in London 8 minutes (i.e., 640m) and 12 minutes (i.e., 960m) were used as the threshold walk distances to bus and rail SAPs, respectively; SAPs beyond these distances are rejected. However, in Ahmedabad, surveys to determine willingness to walk for public transport were not carried out. Therefore, the farthest SAP from a POI (not accounted for in any other POI) was measured, which turned out to be 993m. At 60m/min, this give as willingness to walk at about 16 minutes, which seemed reasonable. 241: 270: 182:
road (the black-top surface), which creates unsafe and potentially hazardous situations, such that walking is avoided as much as possible, even for short trips. To account for this discomfort walk speed was decreased to 60m/min (based on a few samples) as against 80m/min used in London. The reliability factor added in case of London (to allow for additional wait times) were 2 minutes and 0.75 minutes for buses and rail services, respectively. In Ahmedabad, this was changed to 2.5 minutes for city buses (
326:. The methodology adopted for the PTAL analysis of Ahmedabad and Surat was used to prepare the PTAL map of Lucknow. The maps of the baseline and the tentatively committed scenarios formed the basis for further research on its applications to improve the urban plan-making process. The first application of PTAL was to enhance the statutory development plan. The PTAL map was superimposed over the proposed development plan to validate the congruity of the land use and transport proposals (see figure 290:
mobility needs of the urban poor, which is based on another study in Ahmedabad. It argues that living in high PTAL areas may not necessarily translate to high accessibility to destination by public transport, especially those urban poor with variable job destination by month and season (e.g., construction workers, casual labourers, street vendors, etc.). Superimposing the housing location of the urban poor on the PTAL map allows identifying specific areas for enhancing the mobility (see figure
280: 157: 303: 419: 262:) were generated based on information on future (and committed) proposals to demonstrate PTAL's strategic use to create "what-if" scenarios. The Surat study also explicitly justified the use of 1 km grid for PTAL mapping in data and resource constrained situations by showing changes in PTAL map resolutions for grid sizes for comparison (see figure 369:
Recommendations were made to improve public transport infrastructure to ensure synchronisation with the existing job centres and proposed development. The PTAL map was also superimposed on proposed affordable housing locations in the Master Plan to assess accessibility to public transport, and hence,
82:
and trams). These stops and stations are known as service access points (SAPs). Only SAPs within a certain distance of the POI are included (640m for bus stops and 960m for rail stations, which correspond to a walking time of 8 minutes and 12 minutes respectively at the standard assumed walking speed
181:
The others adaptation of London method to Ahmedabad included revisiting walk speed and public transport service reliability assumptions. Most of the roads in Ahmedabad do not have footpaths and, if any, are usually occupied by street vendors and parking. Therefore, people are forced to walk on the
289:
The Surat study discussed several uses of PTAL mapping such as: prioritising public transport investments Integrating transport in development/master plan informing the parking policy improving residential location choice and optimizing the supply of affordable housing, and understanding the
208:
Integrating land use zoning with public transport accessibility. By allowing future transport improvements to be incorporated into PTAL calculations, a future PTAL map becomes an important tool in supporting land use and zoning decisions for local authorities, including introduce transit-oriented
41:
PTAL is a simple, easily calculated approach that hinges on the distance from any point to the nearest public transport stop, and service frequency at those stops. The result is a grade from 1–6 (including sub-divisions 1a, 1b, 6a and 6b), where a PTAL of 1a indicates extremely poor access to the
497:
The use of arbitrary cut-offs to exclude more distant service access points underestimates the ability to access locations just outside those cut-off distances. For example, a point 960m from King's Cross could have a PTAL of 6, whilst a point 961m from the same station could have a PTAL of 1 or
86:
The next stage is to determine the service level during the morning peak (defined as 0815–0915) for each route serving a SAP. Where service levels differ in each direction on a route, the highest frequency is taken. On railways, a route is generally defined as a service with a particular calling
357:
In the study, the PTAL map was superimposed with the proposed Master Plan 2031, which envisions Hubli-Dharwad to grow as a compact and equitable city. A key methodological step was to start with the base year PTAL map and overlay layers of existing land use, job density, development and demand
220:
PTAL maps could be used by households to inform their residential location choices, especially low-income households that are captive public transport users. Real estate developers (who supply housing and commercial spaces) could use PTAL maps (both existing and future) for locating potential
350:) that can further be used to facilitate the decision-making process in master plan preparation and guide future public transport investments, rationalise land use distribution, help decide sites for affordable housing locations, and support the demarcation of transit-oriented development ( 513:– journey time contours – within which the number of workplaces, households or residents can be calculated using census data. This method takes into account many more factors than PTAL, but is much more time-consuming and requires a level of expertise with GIS software and methodologies. 136:) must follow planning guidelines that allow more parking in areas with low PTALs (i.e., poor public transport) and vice versaβ€”and that also relate the allowed density of development to PTAL (i.e., areas with better public transport may have higher density housing or offices). 102:). This is converted to an equivalent doorstep frequency (EDF) by dividing 30 (minutes) by the total access time, which is intended to convert total access time to a "notional average waiting time, as though the route were available at the doorstep of the POI". 258:) demonstrating a better way to use PTAL maps to inform public transport investment decisions. Second, it demonstrates the use of PTAL for evaluating future transport investment options. PTAL maps for year 2021 (see figure 201:
Improving existing public transport systems by recognizing areas with poor accessibility, thereby enabling decision makers to prioritize investments in public transport systems and support non-motorized transport
112:
Finally, the EDF and the weighting are multiplied to produce an accessibility index for each route, and the accessibility indices for all routes are summed to produce an overall accessibility index for the POI.
493:
It does not take into account where services actually go to – for example, a bus that runs every ten minutes to the bottom of the road is considered better than a bus that runs every twelve minutes to the city
205:
Formulating parking policies, e.g. park-and-ride facilities could be provided to supplement areas with low and medium PTAL and parking may be restricted or charged at a higher rate in areas with high PTAL.
370:
recommendations were made to improve connectivity to these zones. The proposed TOD zone demarcation along the BRT corridor was also overlaid on the PTAL map to validate accessibility levels in the zone.
116:
This accessibility index (AI) can then be converted to a PTAL grade (1–6) through a banding system (where AIs 0.00–5.00 are PTAL 1, 5.01–10.00 are PTAL 2, etc. up to PTAL 6 for scores of 25 and above).
334:). The authors also proposed combining this tool to develop a holistic dashboard; this could be used by the stakeholders in making more informed decisions focused on land use transport integration. 929: 266:). Of course, smaller grid micro-PTAL maps can be prepared for specific areas of the city, which could be used to fine-tune public transport infrastructure provision at the local area level. 98:
A total access time for each route is then calculated by adding together the walking time from the POI to the SAP and the average waiting time for services on the route (i.e. half the
254:
by Bhargav Adhvaryu, Abhay Chopde, and Lalit Dashora. This application goes beyond the Ahmedabad study in two ways. First, it overlays population density map on PTAL maps (see figure
105:
A weighting is applied to each route to simulate the enhanced reliability and attractiveness of a route with a higher frequency over other routes. For each mode (e.g. bus, Tube,
217:
criteria from POIs – an important D (distance to transit) in the 6Ds of TOD. It can also be useful in testing "what if" scenarios using land use – transport interaction models.
713:
Adhvaryu, Bhargav; Chopde, Abhay; Dashora, Lalit (1 June 2019). "Mapping public transport accessibility levels (PTAL) in India and its applications: A case study of Surat".
389:(GMAL) method. This is similar to the PTAL calculation but uses "crow flies" distances to Service Access Points. It also includes an additional score for "Local Link" 128:
The PTAL is used as a development planning tool in London, to determine both permitted parking standards and development densities. Large site developments (those the
502: 633: 621: 936: 897: 1095: 906:– a paper presented to a PTRC conference proposing an alternative accessibility modelling approach to public transport accessibility calculations 70:
The first stage in PTAL calculation is to calculate the walking distance from the site (known as the point of interest (POI)) to the nearest
516: 366:). As can be seen, the average accessibility index in the base year (2020) is 3.6 (buses/hour), which improves to 5.5 buses/hour for 2031. 221:
projects (especially low-income housing and industrial), while government agencies could use PTAL maps to locate social housing projects.
645: 109:, tram, rail), the route with the highest frequency is given a weighting of 1.0, with all other routes in that mode weighted at 0.5. 509:
to calculate door-to-door travel times by public transport to a grid of points around the point of interest, resulting in a set of
183: 909: 882: 757: 634:
https://tfl.gov.uk/info-for/media/press-releases/2015/april/planners-gain-access-more-data-to-help-plan-more-effectively
187: 1054: 622:
http://data.london.gov.uk/dataset/public-transport-accessibility-levels/resource/86bbffe1-8af1-49ba-ac9b-b3eacaf68137
565: 462: 58:
in 2004 as the standard method for calculation of public transport access in London. It is not commonly used outside
51: 444: 1090: 922: 781:"Public transport accessibility mapping and its urban planning policy applications: A case study of Lucknow, India" 609: 379: 475: 485:
Whilst PTAL is a simple calculation (easily performed by a spreadsheet) that offers an obvious indication of the
429: 436: 402: 358:
potential, PT improvement leading to a robust public-transport centric development plan for 2031 (see figure
1013: 351: 210: 390: 962: 904:
Advances in public transport accessibility assessments for development control – a proposed methodology
553: 1008: 532: 823:"Visualising public transport accessibility to inform urban planning policy in Hubli-Dharwad, India" 870: 230: 133: 946: 440: 190:(based on empirical observations), and 0.75 minutes was not changed for the proposed metrorail – 106: 79: 354:) zone demarcation. The base year PTAL is also important to compare the PTALs with future year. 143:
and timetable data, the typical result being a map with coloured bands relating to PTAL grades.
42:
location by public transport, and a PTAL of 6b indicates excellent access by public transport.
22:
Public transport in action – pedestrians boarding a bus at Canada Water bus station in London.
18: 1034: 559: 957: 362:). Considering these future (2031) PT improvements, the PTAL was then prepared (see figure 55: 903: 8: 95:
could be divided into two "routes": Cockfosters to Heathrow and Cockfosters to Uxbridge.
521:
Hubli-Dharwad PTAL 2031 (future year) with bus rapid transit and mini-bus feeder systems
364:
Hubli-Dharwad PTAL 2031 (future year) with bus rapid transit and mini-bus feeder systems
312: 1018: 883:
https://opendata.transport.nsw.gov.au/dataset/ptal-public-transport-accessibility-level
855: 800: 738: 384: 75: 31: 972: 842: 804: 742: 730: 692: 343: 1044: 1003: 982: 850: 834: 792: 722: 682: 577: 240: 269: 1039: 998: 967: 191: 129: 88: 914: 822: 610:
https://www.whatdotheyknow.com/request/historical_ptal_public_transport?unfold=1
838: 796: 726: 571: 59: 348:
Hubli-Dharwad PTAL 2020 (base year) overlaid on 2011 Census population density
235:
Hubli-Dharwad PTAL 2020 (base year) overlaid on 2011 Census population density
1084: 1064: 846: 780: 734: 696: 687: 670: 548: 510: 342:
The PTAL analysis of Indian cities continued with the application of PTAL to
322:
The PTAL analysis of Indian cities continued with the application of PTAL to
35: 279: 543: 1069: 1049: 977: 214: 92: 156: 537: 489:
of public transport provision in an area, it suffers two key problems:
302: 167: 447:. Statements consisting only of original research should be removed. 328:
Lucknow PTAL 2020 (baseline scenario) overlaid on population density
307:
Lucknow PTAL 2020 (baseline scenario) overlaid on population density
166:
The London PTAL method was first applied in the Indian context to
139:
TfL also have software to calculate PTALs across wide areas using
568: β€“ Measure of passenger capacity of a transportation network 323: 99: 74:
stops and rail stations (where rail can be taken to also include
871:
http://www.gmtu.gov.uk/gmbusroute/GMAL%20Calculation%20Guide.pdf
480:
Methodology to arrive at a robust PT-centric future plan (2031)
360:
Methodology to arrive at a robust PT-centric future plan (2031)
292:
Ahmedabad PTAL 2017 superimposed with slum and chawl location
284:
Ahmedabad PTAL 2017 superimposed with slum and chawl location
251: 250:
Building from the Ahmedabad case study, PTAL was applied for
671:"Public Transport Accessibility Levels for Ahmedabad, India" 540: β€“ High passenger vehicle occupancy leading to crushing 197:
The Ahmedabad study discussed several uses of PTAL mapping:
821:
Adhvaryu, Bhargav; Mudhol, Sushmita S. (23 November 2021).
505:
has been proposed as a solution to these problems. It uses
506: 140: 71: 120:
TfL introduced the WebCAT automatic calculator in 2015.
178:). In addition, it made the computations much faster. 712: 274:
Comparison of PTAL map for various grid sizes (Surat)
264:
Comparison of PTAL map for various grid sizes (Surat)
50:
The PTAL calculation was originally developed by the
944: 646:"Measuring Public Transport Accessibility Levels" 408: 405:also uses an adapted version of the PTAL method. 1082: 756:Adhvaryu, Bhargav; Patel, Mukesh (5 June 2015). 562: β€“ Capacity utilization of public transport 256:Surat PTAL 2016 overlaid with population density 910:– TfL PTAL Calculator with map to select point 820: 930: 900:in the London Plan, which are linked to PTALs 758:"Is Public Transport in Ahmedabad Inclusive?" 755: 146: 30:is a method sometimes used in United Kingdom 668: 556: β€“ Number of passengers using a service 38:of geographical areas to public transport. 28:public transport accessibility level (PTAL) 937: 923: 854: 778: 686: 463:Learn how and when to remove this message 869:Greater Manchester Transportation Unit, 515: 474: 311: 301: 278: 268: 239: 229: 155: 17: 87:pattern – for example, services on the 1096:Public transport in the United Kingdom 1083: 918: 669:Shah, Jay; Adhvaryu, Bhargav (2016). 373: 1060:Public transport accessibility level 816: 814: 708: 706: 664: 662: 660: 658: 412: 580: β€“ Unequal access to transport 13: 779:Adhvaryu, Bhargav; Kumar, Sameer. 397: 54:in 1992, and was later adopted by 14: 1107: 1055:Passengers per hour per direction 891: 811: 703: 655: 566:Passengers per hour per direction 175: 52:Borough of Hammersmith and Fulham 785:Case Studies on Transport Policy 715:Case Studies on Transport Policy 675:Journal of Public Transportation 417: 380:Transport for Greater Manchester 337: 260:Surat PTAL 2016 v. 2021 (future) 245:Surat PTAL 2016 v. 2021 (future) 213:), as PTALs already incorporate 875: 863: 574: β€“ Area lacking in transit 881:Transport for New South Wales 772: 749: 638: 626: 614: 602: 409:Advantages & disadvantages 62:or the south east of England. 1: 762:Economic and Political Weekly 584: 403:Transport for New South Wales 45: 1014:Transit-oriented development 332:Lucknow PTAL: Macro v. Micro 317:Lucknow PTAL: Macro v. Micro 151: 7: 526: 443:the claims made and adding 391:demand responsive transport 10: 1112: 963:Transportation forecasting 839:10.1007/s10708-021-10548-6 797:10.1016/j.cstp.2021.08.001 727:10.1016/j.cstp.2019.03.004 554:Patronage (transportation) 297: 147:Application in other areas 1027: 1009:Green transport hierarchy 991: 953: 533:Accessibility (transport) 65: 688:10.5038/2375-0901.19.3.2 225: 134:Greater London Authority 1091:Transportation planning 947:transportation planning 503:Accessibility modelling 123: 523: 482: 319: 309: 286: 276: 247: 237: 163: 23: 1035:Automobile dependency 560:Passenger load factor 519: 478: 315: 305: 282: 272: 243: 233: 159: 21: 958:Land use forecasting 170:in 2014 (see figure 56:Transport for London 387:Accessibility Level 186:) and 1 minute for 172:Ahmedabad PTAL 2014 161:Ahmedabad PTAL 2014 1028:Modal measurements 1019:Pedestrian village 524: 483: 428:possibly contains 385:Greater Manchester 374:Greater Manchester 320: 310: 287: 277: 248: 238: 164: 76:London Underground 32:transport planning 24: 1078: 1077: 973:Trip distribution 898:Parking standards 620:London Datastore 473: 472: 465: 430:original research 176:Surat application 1103: 1045:Cycling mobility 1004:Bicycle friendly 983:Route assignment 939: 932: 925: 916: 915: 885: 879: 873: 867: 861: 860: 858: 818: 809: 808: 791:(4): 1503–1517. 776: 770: 769: 753: 747: 746: 710: 701: 700: 690: 666: 653: 652: 650: 642: 636: 630: 624: 618: 612: 606: 597: 596: 592: 578:Transport divide 468: 461: 457: 454: 448: 445:inline citations 421: 420: 413: 1111: 1110: 1106: 1105: 1104: 1102: 1101: 1100: 1081: 1080: 1079: 1074: 1040:Bicycle counter 1023: 999:Automotive city 987: 968:Trip generation 949: 943: 894: 889: 888: 880: 876: 868: 864: 833:(S4): 485–509. 819: 812: 777: 773: 754: 750: 711: 704: 667: 656: 648: 644: 643: 639: 631: 627: 619: 615: 607: 603: 598: 594: 590: 588: 587: 529: 469: 458: 452: 449: 434: 422: 418: 411: 400: 398:New South Wales 376: 340: 300: 228: 202:infrastructure. 192:Ahmedabad Metro 154: 149: 130:London boroughs 126: 89:Piccadilly line 68: 48: 12: 11: 5: 1109: 1099: 1098: 1093: 1076: 1075: 1073: 1072: 1067: 1062: 1057: 1052: 1047: 1042: 1037: 1031: 1029: 1025: 1024: 1022: 1021: 1016: 1011: 1006: 1001: 995: 993: 992:Modes favoured 989: 988: 986: 985: 980: 975: 970: 965: 960: 954: 951: 950: 942: 941: 934: 927: 919: 913: 912: 907: 901: 893: 892:External links 890: 887: 886: 874: 862: 810: 771: 748: 721:(2): 293–300. 702: 654: 637: 625: 613: 600: 599: 586: 583: 582: 581: 575: 572:Transit desert 569: 563: 557: 551: 546: 541: 535: 528: 525: 511:isochrone maps 500: 499: 495: 471: 470: 425: 423: 416: 410: 407: 399: 396: 395: 394: 382:developed the 375: 372: 339: 336: 299: 296: 227: 224: 223: 222: 218: 206: 203: 153: 150: 148: 145: 125: 122: 67: 64: 60:Greater London 47: 44: 34:to assess the 9: 6: 4: 3: 2: 1108: 1097: 1094: 1092: 1089: 1088: 1086: 1071: 1068: 1066: 1065:Traffic count 1063: 1061: 1058: 1056: 1053: 1051: 1048: 1046: 1043: 1041: 1038: 1036: 1033: 1032: 1030: 1026: 1020: 1017: 1015: 1012: 1010: 1007: 1005: 1002: 1000: 997: 996: 994: 990: 984: 981: 979: 976: 974: 971: 969: 966: 964: 961: 959: 956: 955: 952: 948: 940: 935: 933: 928: 926: 921: 920: 917: 911: 908: 905: 902: 899: 896: 895: 884: 878: 872: 866: 857: 852: 848: 844: 840: 836: 832: 828: 824: 817: 815: 806: 802: 798: 794: 790: 786: 782: 775: 767: 763: 759: 752: 744: 740: 736: 732: 728: 724: 720: 716: 709: 707: 698: 694: 689: 684: 680: 676: 672: 665: 663: 661: 659: 647: 641: 635: 629: 623: 617: 611: 605: 601: 593: 579: 576: 573: 570: 567: 564: 561: 558: 555: 552: 550: 549:Isochrone map 547: 545: 542: 539: 536: 534: 531: 530: 522: 518: 514: 512: 508: 504: 496: 492: 491: 490: 488: 481: 477: 467: 464: 456: 453:February 2022 446: 442: 438: 432: 431: 426:This section 424: 415: 414: 406: 404: 392: 388: 386: 381: 378: 377: 371: 367: 365: 361: 355: 353: 349: 345: 344:Hubli-Dharwad 338:Hubli-Dharwad 335: 333: 329: 325: 318: 314: 308: 304: 295: 293: 285: 281: 275: 271: 267: 265: 261: 257: 253: 246: 242: 236: 232: 219: 216: 212: 209:development ( 207: 204: 200: 199: 198: 195: 193: 189: 185: 179: 177: 173: 169: 162: 158: 144: 142: 137: 135: 132:refer to the 131: 121: 118: 114: 110: 108: 103: 101: 96: 94: 90: 84: 83:of 80m/min). 81: 77: 73: 63: 61: 57: 53: 43: 39: 37: 33: 29: 20: 16: 1059: 877: 865: 830: 826: 788: 784: 774: 765: 761: 751: 718: 714: 681:(3): 19–35. 678: 674: 640: 628: 616: 604: 544:Forced rider 520: 501: 486: 484: 479: 459: 450: 427: 401: 383: 368: 363: 359: 356: 347: 341: 331: 327: 321: 316: 306: 291: 288: 283: 273: 263: 259: 255: 249: 244: 234: 196: 180: 171: 165: 160: 138: 127: 119: 115: 111: 104: 97: 85: 69: 49: 40: 36:access level 27: 25: 15: 1070:Walkability 1050:Modal share 978:Mode choice 215:walkability 93:Hammersmith 1085:Categories 827:GeoJournal 585:References 538:Crush load 437:improve it 294:).   46:Background 847:0343-2521 805:238682808 768:(8): 7–8. 743:169155963 735:2213-624X 697:1077-291X 441:verifying 393:services. 168:Ahmedabad 152:Ahmedabad 527:See also 856:8609270 589:s": --> 494:centre. 487:density 435:Please 324:Lucknow 298:Lucknow 100:headway 945:Urban 853:  845:  803:  741:  733:  695:  66:Method 801:S2CID 739:S2CID 649:(PDF) 252:Surat 226:Surat 91:from 843:ISSN 731:ISSN 693:ISSN 632:TfL 608:FOI 591:edit 188:BRTS 184:AMTS 124:Uses 26:The 851:PMC 835:doi 793:doi 723:doi 683:doi 507:GIS 439:by 352:TOD 211:TOD 141:GIS 107:DLR 80:DLR 72:bus 1087:: 849:. 841:. 831:87 829:. 825:. 813:^ 799:. 787:. 783:. 766:54 764:. 760:. 737:. 729:. 717:. 705:^ 691:. 679:19 677:. 673:. 657:^ 498:2. 78:, 938:e 931:t 924:v 859:. 837:: 807:. 795:: 789:9 745:. 725:: 719:7 699:. 685:: 651:. 595:] 466:) 460:( 455:) 451:( 433:.

Index


transport planning
access level
Borough of Hammersmith and Fulham
Transport for London
Greater London
bus
London Underground
DLR
Piccadilly line
Hammersmith
headway
DLR
London boroughs
Greater London Authority
GIS

Ahmedabad
Surat application
AMTS
BRTS
Ahmedabad Metro
TOD
walkability


Surat


Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.

↑