Brownell & Germain 1
Chris Brownell
Sarah Germain
ORF 467
MyCity Project
October 25, 2011
Newburgh Trip Distribution Report
The City of Newburgh: Land Use
Since its founding in 1811, Newburgh has grown from a small trading outpost into a truly cosmopolitan city of 250,000 people. Situated on the west banks of the Bluewater River, it is often referred to as the “Gem of the Bluewater,” renowned for its glistening downtown, spacious and clean parks, and world-class entertainment venues. A map of Newburgh can be seen below, divided into colored sections based on land use.Newburgh’s current total area is 102.4 mi².
In an effort to learn more about the transportation needs of Newburgh’s citizens in this its bicentennial year, we have divided it into 80 zones, each one with a distinct land use. The river and lakes are unzoned, while the parks (including Gull Island, one of the city’s most popular weekend picnic spots) are zoned. The city is comprised of just under 33% undeveloped area, which includes both water and parkland. Land use by square mileage and percent of total area can be seen in the above chart.
Downtown Newburgh is located along the southern portion of the Bluewater River, in the city’s southeast corner. Downtown consists of high-occupancy apartments, high-occupancy retail shops and restaurants, an entertainment district, government center, and Centennial Park, which borders the government and entertainment districts. Because Newburgh’s current downtown was the original site of the settlement in 1811, the remainder of the city has grown up around this area. Heavy manufacturing facilities are concentrated downriver from the city center, to the north, and single-family residential areas have arisen in almost every direction surrounding downtown. The urban housing projects are located inland at the south edge of town, bordering a manufacturing district where a portion of its residents are employed. The newest portion of town is the northwest corner, which houses the university, airport, and the city’s growing high-tech business center. And we would be loath not to mention the city’s world famous zoo, which is located essentially equidistant between downtown, the university center, and the wealthy homes surrounding Trout Lake.
Newburgh’s Greatest Treasure: The People Who Live Here
In the first of the two charts shown above, Newburgh’s population of 250,000 is broken down by age group. The population breakdown of Newburgh by age is in fact very similar to that of the entire United States. 2010 Census data shows that some 53% of Americans are adults between the ages of 25 and 65, as compared to 65% of Newburgh residents. 6.5% of Americans are under 5, as compared to 5% of Newburgh residents, and 17.5% are aged 5 to 17, as opposed to Newburgh’s 13%. Youths from age 18 to 24 make up about 10% of the U.S. and about 9% of Newburgh, while the elderly round out both populations at 13% for the U.S. and 8% in Newburgh. The percentage of working-age residents is considerable higher than the national average, but with the booming industry and countless entertainment options in Newburgh, who can blame them?
Each member of the Newburgh population can also be characterized by what we call a “person-type.” People in the same person-type category often behave in similar ways, making it easier to model their movement throughout the city on an average day. The person-type breakdown is contained in the second chart. Some 60% of Newburgh residents are job-seeking adults, but just over 2.5% of the total population is sadly unemployed job-seekers. These people, along with the elderly, dependents, and those who choose not to work, comprise the “at-home parents & non-workers” category. As the chart below indicates, 83% of all adults are job seekers, as are 90% of non-university-attending 18 to 24-year-olds, and 15% of people over 65. While it would be nice to think that all elderly residents of Newburgh don’t have to work, it is simply not the case.
The job-seeking population can be broken down even further based upon what job, if any, they hold. Those numbers are included in the chart above. Each zone in Newburgh has a capacity (per square mile) for workers or residents, depending upon what its land-use type is. The capacities and total employment/residency numbers are included in the charts below.
The university acts as both a residence and a place of work, as all 8550 students live on campus, while the staff of 4500 travel from their homes throughout the city to get to work each day.
Trip Generation:
Trips in our city are broadly categorized into Home-Based and Non-Home-Based trips, covering trip types that originate at the home and those that do not. Home-Based trips are split into 3 categories: Home-Based Work, Home-Based School, and Home-Based Recreation. Non-Home-Based trips are split into 3 categories: Recreation-Based Recreation, School-Based Recreation, and Work-Based Recreation. These can be thought of as Other-to-Other trips, in which the person neither leaves from home nor arrives at home as their destination.
When constructing the P&A arrays, we assumed that each zone had a fixed capacity per square mile and thus it’s total capacity depended solely on the type of zone and the size of the zone. Capacities of each type of zone, as shown in the previous sections, are translated into the column called “People” in the P&A arrays.
We also made sure that all of the production and attraction vectors equaled one another for each type of trip.
For the Home-Based trips, only the residential zones are non-zero in the productions arrays since all of the trips originate at the home. Likewise, because all of the trips end somewhere other than home, the recreational zones all have zero in their attractions arrays. We assume that 100% of the to-work and to-school trips are Home-Based. We also assume that all Home-Based trips are round trips, that is to say that people will always return home at the end of the day.
Home-Based Work (HB-Work) trips are between residential areas and areas of employment. In order to generate the production arrays, we used the fact that 57.43% of the citizens of Newburgh are Job-Holding Workers. Thus, the production array is .5743 times the total density of the residential area. The attraction array is simply the number of jobs offered in a particular zone. Further, we assume that the university residences produce no workers, but attract workers that represent the professors who do not live on campus and have to commute.
Home-Based School (HB-School) trips are students’ trips from residential areas to their schools. In order to generate the production arrays, we used the fact that 13.00% of the citizens of Newburgh are School-Age Children. Thus, the production array is .13 times the total density of the residential area. The attraction array is simply the capacity of each school (which we made equal among all of the schools in our city).
Home-Based Recreation (HB-Rec) trips are trips from home to areas with retail, restaurants, and recreation (open space, parks, zoo, library, entertainment). In order to generate the production and attraction of these leisure trips, we looked at the demographics of our city to determine a reasonable number of people who would be making these trips (elderly, unemployed, stay-at-home parents with dependents), as well as making some assumptions about the number of visitors at each recreational area per day. The number of visitors to the zoo and the airport were approximated based on real-life data.
Leisure Trips Assumptions / Visitors/Sq Mile / Total / PercentageOpen Space / 4500 / 49950 / 12.31%
Light Retail/Restaurant / 30000 / 141000 / 34.76%
High Retail/Restaurant / 60000 / 156000 / 38.46%
Library / 2000 / 600 / 0.15%
Zoo / 10000 / 4000 / 0.99%
Entertainment / 20000 / 50000 / 12.33%
Airport Passengers per day / 8220 / 8220 / 1.01%
Total / 405660 / 100.00%
The resulting production and attraction vectors are shown below for each of the three Home-Based trip purposes.
Home-Based Productions and Attractions:
HB-work / HB-school / HB-recTAZ / Type / People / P / A / P / A / P / A
1 / AP / 2,400 / - / 2,400 / - / - / - / 2,055
2 / HT / 6,000 / - / 6,000 / - / - / - / -
3 / LT / 1,800 / - / 1,800 / - / - / - / -
4 / OP / - / - / - / - / - / - / -
5 / LM / 13,800 / - / 13,800 / - / - / - / -
6 / HM / 9,500 / - / 9,500 / - / - / - / -
7 / OP / - / - / - / - / - / - / -
8 / LT / 5,400 / - / 5,400 / - / - / - / -
9 / HS / 9,750 / 5,867 / - / 1,313 / - / 7,910 / -
10 / LS / 7,000 / 4,212 / - / 942 / - / 5,679 / -
11 / EN / 2,000 / - / 2,000 / - / - / - / 10,000
12 / HS / 18,000 / 10,831 / - / 2,423 / - / 14,604 / -
13 / OP / - / - / - / - / - / - / -
14 / LR / 2,400 / - / 2,400 / - / - / - / 12,000
15 / LO / 6,800 / - / 6,800 / - / - / - / -
16 / LR / 600 / - / 600 / - / - / - / 3,000
17 / UN / 8,550 / - / - / 8,550 / 8,550 / 6,937 / -
18 / HM / 4,600 / 2,768 / - / 619 / - / 3,732 / -
19 / HR / 2,200 / - / 2,200 / - / - / - / 12,000
20 / HO / 13,500 / - / 13,500 / - / - / - / -
21 / OP / - / - / - / - / - / - / 1,350
22 / GV / 1,200 / - / 1,200 / - / - / - / -
23 / SC / 400 / - / 400 / - / 2,955 / - / -
24 / LM / 5,950 / 3,580 / - / 801 / - / 4,827 / -
25 / SC / 400 / - / 400 / - / 2,955 / - / -
26 / LB / 30 / - / 30 / - / - / - / 100
27 / LR / 1,200 / - / 1,200 / - / - / - / 6,000
28 / SC / 400 / - / 400 / - / 2,955 / - / -
29 / SC / 400 / - / 400 / - / 2,955 / - / -
30 / HM / 18,400 / 11,072 / - / 2,477 / - / 14,928 / -
31 / LO / 2,800 / - / 2,800 / - / - / - / -
32 / LS / 9,000 / 5,415 / - / 1,212 / - / 7,302 / -
33 / LO / 4,000 / - / 4,000 / - / - / - / -
34 / ZO / 280 / - / 280 / - / - / - / 2,000
35 / LS / 4,000 / 2,407 / - / 538 / - / 3,245 / -
36 / LS / 8,500 / 5,115 / - / 1,145 / - / 6,896 / -
37 / LM / 17,000 / 10,229 / - / 2,288 / - / 13,792 / -
38 / SC / 400 / - / 400 / - / 2,955 / - / -
39 / HR / 6,600 / - / 6,600 / - / - / - / 36,000
40 / GV / 2,700 / - / 2,700 / - / - / - / -
41 / OP / - / - / - / - / - / - / 2,700
42 / HM / 18,400 / 11,072 / - / 2,477 / - / 14,928 / -
43 / LM / 16,150 / 9,718 / - / 2,174 / - / 13,103 / -
44 / SC / 400 / - / 400 / - / 2,955 / - / -
45 / OP / - / - / - / - / - / - / 2,700
46 / EN / 1,200 / - / 1,200 / - / - / - / 6,000
47 / HT / 2,000 / - / 2,000 / - / - / - / -
48 / OP / - / - / - / - / - / - / 2,025
49 / HS / 23,250 / 13,358 / - / 3,129 / - / 18,863 / -
50 / HR / 5,500 / - / 5,500 / - / - / - / 30,000
51 / EN / 1,800 / - / 1,800 / - / - / - / 9,000
52 / HO / 19,500 / - / 19,500 / - / - / - / -
53 / HM / 11,500 / 6,920 / - / 1,548 / - / 9,330 / -
54 / LB / 30 / - / 30 / - / - / - / 100
55 / LM / 12,750 / 7,672 / - / 1,717 / - / 10,344 / -
56 / SC / 400 / - / 400 / - / 2,955 / - / -
57 / LO / 2,400 / - / 2,400 / - / - / - / -
58 / LR / 4,500 / - / 4,500 / - / - / - / 22,500
59 / HS / 9,000 / 5,415 / - / 1,212 / - / 7,302 / -
60 / HS / 24,000 / 13,358 / - / 3,230 / - / 19,472 / -
61 / LR / 2,400 / - / 2,400 / - / - / - / 12,000
62 / SC / 400 / - / 400 / - / 2,955 / - / -
63 / OP / - / - / - / - / - / - / 2,700
64 / SC / 400 / - / 400 / - / 2,955 / - / -
65 / HM / 9,200 / 5,536 / - / 1,238 / - / 7,464 / -
66 / LR / 900 / - / 900 / - / - / - / 4,500
67 / LM / 3,600 / - / 3,600 / - / - / - / -
68 / LO / 3,200 / - / 3,200 / - / - / - / -
69 / LS / 4,500 / 2,708 / - / 605 / - / 3,651 / -
70 / SC / 400 / - / 400 / - / 2,955 / - / -
71 / LS / 4,500 / 2,708 / - / 605 / - / 3,651 / -
72 / LS / 6,000 / 3,610 / - / 807 / - / 4,868 / -
73 / LB / 30 / - / 30 / - / - / - / 100
74 / SC / 400 / - / 400 / - / 2,955 / - / -
75 / OP / - / - / - / - / - / - / 7,425
76 / LR / 1,500 / - / 1,500 / - / - / - / 7,500
77 / GV / 300 / - / 300 / - / - / - / -
78 / OP / - / - / - / - / - / - / 6,075
79 / LR / 600 / - / 600 / - / - / - / 3,000
80 / UN / 4,500 / - / 4,500 / - / - / - / -
TOTAL / 143,570 / 143,570 / 41,050 / 41,050 / 202,830 / 202,830
One Way / 287,140 / 82,100 / 405,660
For the Non-Home-Based trips, all of the residential zones are zero in the productions arrays since all of the trips originate at a location other than at the home. Likewise, because all of the trips end somewhere other than the home, recreational zones are always zero in the attractions arrays. We assume that 80% of the from-home and from-school trips are home-based, meaning that 20% of workers and students go to a recreational zone after work or school. We also assume that 50% of the to-shopping and from-shopping trips are home-based, meaning that 50% of people leaving a recreational zone will head to another recreational destination before heading home. We assumed that all Non-Home-Based trips are one-way trips, since it would not make sense for them to be round trips heading back to a recreational areas at the end of the day.
Recreation-Based Recreation (RB-Rec) trips are between recreational areas. For the production arrays, we assumed that 50% of people leaving a recreational zone will head to another recreational destination before heading home, so the productions of each zone roughly equals the attractions of that same zone. For the attraction arrays, we used the “Leisure Trip Assumptions” in the chart above.
School-Based Recreation (SB-Rec) trips are students’ trips from school to recreational areas. For the production arrays, we assumed that 20% of students go to a recreational zone after school. Again, for the attraction arrays, we used the “Leisure Trip Assumptions” in the chart above.
Work-Based Recreation (WB-Rec) trips are workers’ trips from work to recreational areas. For the production arrays, we assumed that 20% of workers go to a recreational zone after work. Again, for the attraction arrays, we used the “Leisure Trip Assumptions” in the chart above.
The resulting production and attraction vectors are shown below for each of the three Non-Home-Based trip purposes.
Non-Home-Based Productions and Attractions:
NHB / NHB / NHB / NHBTotal / RB-rec / SB-rec / WB-rec
TAZ / Type / People / P / A / P / A / P / A / P / A
1 / AP / 2,400 / 4,590 / 2,055 / 4,110 / 1,698 / - / 66 / 480 / 291
2 / HT / 6,000 / 1,200 / - / - / - / - / - / 1,200 / -
3 / LT / 1,800 / 360 / - / - / - / - / - / 360 / -
4 / OP / - / - / - / - / - / - / - / - / -
5 / LM / 13,800 / 2,760 / - / - / - / - / - / 2,760 / -
6 / HM / 9,500 / 1,900 / - / - / - / - / - / 1,900 / -
7 / OP / - / - / - / - / - / - / - / - / -
8 / LT / 5,400 / 1,080 / - / - / - / - / - / 1,080 / -
9 / HS / 9,750 / - / - / - / - / - / - / - / -
10 / LS / 7,000 / - / - / - / - / - / - / - / -
11 / EN / 2,000 / 8,535 / 10,000 / 8,135 / 8,264 / - / 320 / 400 / 1,416
12 / HS / 18,000 / - / - / - / - / - / - / - / -
13 / OP / - / - / - / - / - / - / - / - / -
14 / LR / 2,400 / 10,242 / 12,000 / 9,762 / 9,917 / - / 385 / 480 / 1,699
15 / LO / 6,800 / 1,360 / - / - / - / - / - / 1,360 / -
16 / LR / 600 / 2,560 / 3,000 / 2,440 / 2,479 / - / 96 / 120 / 425
17 / UN / 8,550 / - / - / - / - / - / - / - / -
18 / HM / 4,600 / - / - / - / - / - / - / - / -
19 / HR / 2,200 / 10,202 / 12,000 / 9,762 / 9,917 / - / 385 / 440 / 1,699
20 / HO / 13,500 / 2,700 / - / - / - / - / - / 2,700 / -
21 / OP / - / 1,098 / 1,350 / 1,098 / 1,116 / - / 43 / - / 191
22 / GV / 1,200 / 240 / - / - / - / - / - / 240 / -
23 / SC / 400 / 671 / - / - / - / 591 / - / 80 / -
24 / LM / 5,950 / - / - / - / - / - / - / - / -
25 / SC / 400 / 671 / - / - / - / 591 / - / 80 / -
26 / LB / 30 / 90 / 100 / 84 / 83 / - / 3 / 6 / 14
27 / LR / 1,200 / 5,301 / 6,000 / 5,061 / 4,958 / - / 192 / 240 / 849
28 / SC / 400 / 671 / - / - / - / 591 / - / 80 / -
29 / SC / 400 / 671 / - / - / - / 591 / - / 80 / -
30 / HM / 18,400 / - / - / - / - / - / - / - / -
31 / LO / 2,800 / 560 / - / - / - / - / - / 560 / -
32 / LS / 9,000 / - / - / - / - / - / - / - / -
33 / LO / 4,000 / 800 / - / - / - / - / - / 800 / -
34 / ZO / 280 / 1,683 / 2,000 / 1,627 / 1,653 / - / 64 / 56 / 283
35 / LS / 4,000 / - / - / - / - / - / - / - / -
36 / LS / 8,500 / - / - / - / - / - / - / - / -
37 / LM / 17,000 / - / - / - / - / - / - / - / -
38 / SC / 400 / 671 / - / - / - / 591 / - / 80 / -
39 / HR / 6,600 / 30,605 / 36,000 / 29,285 / 29,750 / - / 1,154 / 1,320 / 5,096
40 / GV / 2,700 / 540 / - / - / - / - / - / 540 / -
41 / OP / - / 2,196 / 2,700 / 2,196 / 2,231 / - / 87 / - / 382
42 / HM / 18,400 / - / - / - / - / - / - / - / -
43 / LM / 16,150 / - / - / - / - / - / - / - / -
44 / SC / 400 / 671 / - / - / - / 591 / - / 80 / -
45 / OP / - / 2,196 / 2,700 / 2,196 / 2,231 / - / 87 / - / 382
46 / EN / 1,200 / 5,121 / 6,000 / 4,881 / 4,958 / - / 192 / 240 / 849
47 / HT / 2,000 / 400 / - / - / - / - / - / 400 / -
48 / OP / - / 1,647 / 2,025 / 1,647 / 1,673 / - / 65 / - / 287
49 / HS / 23,250 / - / - / - / - / - / - / - / -
50 / HR / 5,500 / 25,504 / 30,000 / 24,404 / 24,792 / - / 961 / 1,100 / 4,247
51 / EN / 1,800 / 7,681 / 9,000 / 7,321 / 7,437 / - / 288 / 360 / 1,274
52 / HO / 19,500 / 3,900 / - / - / - / - / - / 3,900 / -
53 / HM / 11,500 / - / - / - / - / - / - / - / -
54 / LB / 30 / 87 / 100 / 81 / 83 / - / 3 / 6 / 14
55 / LM / 12,750 / - / - / - / - / - / - / - / -
56 / SC / 400 / 671 / - / - / - / 591 / - / 80 / -
57 / LO / 2,400 / 480 / - / - / - / - / - / 480 / -
58 / LR / 4,500 / 19,203 / 22,500 / 18,303 / 18,594 / - / 721 / 900 / 3,185
59 / HS / 9,000 / - / - / - / - / - / - / - / -
60 / HS / 24,000 / - / - / - / - / - / - / - / -
61 / LR / 2,400 / 10,242 / 12,000 / 9,762 / 9,917 / - / 385 / 480 / 1,699
62 / SC / 400 / 671 / - / - / - / 591 / - / 80 / -
63 / OP / - / 2,196 / 2,700 / 2,196 / 2,231 / - / 87 / - / 382
64 / SC / 400 / 671 / - / - / - / 591 / - / 80 / -
65 / HM / 9,200 / - / - / - / - / - / - / - / -
66 / LR / 900 / 3,841 / 4,500 / 3,661 / 3,719 / - / 144 / 180 / 637
67 / LM / 3,600 / 720 / - / - / - / - / - / 720 / -
68 / LO / 3,200 / 640 / - / - / - / - / - / 640 / -
69 / LS / 4,500 / - / - / - / - / - / - / - / -
70 / SC / 400 / 671 / - / - / - / 591 / - / 80 / -
71 / LS / 4,500 / - / - / - / - / - / - / - / -
72 / LS / 6,000 / - / - / - / - / - / - / - / -
73 / LB / 30 / 87 / 100 / 81 / 83 / - / 3 / 6 / 14
74 / SC / 400 / 671 / - / - / - / 591 / - / 80 / -
75 / OP / - / 6,040 / 7,425 / 6,040 / 6,136 / - / 238 / - / 1,051
76 / LR / 1,500 / 6,401 / 7,500 / 6,101 / 6,198 / - / 240 / 300 / 1,062
77 / GV / 300 / 60 / - / - / - / - / - / 60 / -
78 / OP / - / 4,942 / 6,075 / 4,942 / 5,020 / - / 195 / - / 860
79 / LR / 600 / 2,560 / 3,000 / 2,440 / 2,479 / - / 96 / 120 / 425
80 / UN / 4,500 / 900 / - / - / - / - / - / 900 / -
TOTAL / 202,830 / 202,830 / 167,616 / 167,616 / 6,500 / 6,500 / 28,714 / 28,714
The resulting total production and attraction vectors are shown below.
Total:
TAZ / Type / People / Total P / Total A1 / AP / 2,400 / 4,590 / 6,510
2 / HT / 6,000 / 1,200 / 6,000
3 / LT / 1,800 / 360 / 1,800
4 / OP / - / - / -
5 / LM / 13,800 / 2,760 / 13,800
6 / HM / 9,500 / 1,900 / 9,500
7 / OP / - / - / -
8 / LT / 5,400 / 1,080 / 5,400
9 / HS / 9,750 / 15,090 / -
10 / LS / 7,000 / 10,833 / -
11 / EN / 2,000 / 8,535 / 22,000
12 / HS / 18,000 / 27,858 / -
13 / OP / - / - / -
14 / LR / 2,400 / 10,242 / 26,400
15 / LO / 6,800 / 1,360 / 6,800
16 / LR / 600 / 2,560 / 6,600
17 / UN / 8,550 / 15,487 / 8,550
18 / HM / 4,600 / 7,119 / -
19 / HR / 2,200 / 10,202 / 26,200
20 / HO / 13,500 / 2,700 / 13,500
21 / OP / - / 1,098 / 2,700
22 / GV / 1,200 / 240 / 1,200
23 / SC / 400 / 671 / 3,355
24 / LM / 5,950 / 9,208 / -
25 / SC / 400 / 671 / 3,355
26 / LB / 30 / 90 / 230
27 / LR / 1,200 / 5,301 / 13,200
28 / SC / 400 / 671 / 3,355
29 / SC / 400 / 671 / 3,355
30 / HM / 18,400 / 28,477 / -
31 / LO / 2,800 / 560 / 2,800
32 / LS / 9,000 / 13,929 / -
33 / LO / 4,000 / 800 / 4,000
34 / ZO / 280 / 1,683 / 4,280
35 / LS / 4,000 / 6,190 / -
36 / LS / 8,500 / 13,156 / -
37 / LM / 17,000 / 26,310 / -
38 / SC / 400 / 671 / 3,355
39 / HR / 6,600 / 30,605 / 78,600
40 / GV / 2,700 / 540 / 2,700
41 / OP / - / 2,196 / 5,400
42 / HM / 18,400 / 28,477 / -
43 / LM / 16,150 / 24,995 / -
44 / SC / 400 / 671 / 3,355
45 / OP / - / 2,196 / 5,400
46 / EN / 1,200 / 5,121 / 13,200
47 / HT / 2,000 / 400 / 2,000
48 / OP / - / 1,647 / 4,050
49 / HS / 23,250 / 35,350 / -
50 / HR / 5,500 / 25,504 / 65,500
51 / EN / 1,800 / 7,681 / 19,800
52 / HO / 19,500 / 3,900 / 19,500
53 / HM / 11,500 / 17,798 / -
54 / LB / 30 / 87 / 230
55 / LM / 12,750 / 19,733 / -
56 / SC / 400 / 671 / 3,355
57 / LO / 2,400 / 480 / 2,400
58 / LR / 4,500 / 19,203 / 49,500
59 / HS / 9,000 / 13,929 / -
60 / HS / 24,000 / 36,060 / -
61 / LR / 2,400 / 10,242 / 26,400
62 / SC / 400 / 671 / 3,355
63 / OP / - / 2,196 / 5,400
64 / SC / 400 / 671 / 3,355
65 / HM / 9,200 / 14,238 / -
66 / LR / 900 / 3,841 / 9,900
67 / LM / 3,600 / 720 / 3,600
68 / LO / 3,200 / 640 / 3,200
69 / LS / 4,500 / 6,964 / -
70 / SC / 400 / 671 / 3,355
71 / LS / 4,500 / 6,964 / -
72 / LS / 6,000 / 9,286 / -
73 / LB / 30 / 87 / 230
74 / SC / 400 / 671 / 3,355
75 / OP / - / 6,040 / 14,850
76 / LR / 1,500 / 6,401 / 16,500
77 / GV / 300 / 60 / 300
78 / OP / - / 4,942 / 12,150
79 / LR / 600 / 2,560 / 6,600
80 / UN / 4,500 / 900 / 4,500
TOTAL / 590,280 / 590,280
One-Way / 977,730
Trips/person / 3.911
Trip Distribution:
In order to calculate the trip distribution for our city, we used the gravity model, which assumes that the trips produced at an origin and attracted to a destination are directly proportional to the total trip productions at the origin and the total attractions at the destination.
In this equation below, the trips between zone i and zone j are given by the gravity model as:
We used Kij = 1, meaning there is no optional adjustment factor. Also, we used 1/(Area)^2 for the "friction factor" (F) for our basic study (the investigate other friction factors in our further analysis section).
To calculate the TripArray matrix for each trip type, we used the gravity model equation to calculate the trips between all possible origins and destinations. We followed the same process for each of the 6 trip types. First, we defined 2 constant matrices.
First, the matrix D represents the distance between zones. We found the coordinates of the centroid of each of our zones. To find the distance, we defined a distance matrix D as the Cartesian distance multiplied by a factor of 1.2 to simulate the circularity of the earth. To find the matrix D’ we adjusted the matrix D by multiplying it 0.316 in order to get the distance in terms of miles. Therefore, D’ represents the transformation of D from our coordinate system to actual miles.
Second, the matrix F represents the “friction factor,” or the reluctance of a person to travel a certain route. We used 1/D^2 as the friction factor for our basic study (the investigate other friction factors in our further analysis section).
The procedure we followed to calculate the TripArray was the same for each of the 6 trip types. We followed the example given to us in lecture. First, we created vectors to represent the production (P) and input attraction (Ainput )arrays. Then, we calculate the Sum matrix, which is the matrix multiplication of array A and matrix F, the friction factors. In order to calculate the TripArray matrix, we multiplied [P/Sum] array by the transpose of Ainput. Then multiplied the resulting matrix by the matrix F.
Because the Gravity Model is doubly constrained, we have to iterate updating the Ainput array until it produces an Aoutput array that is close to our desired A, which is simply the attraction arrays from our P&A arrays. We define C as Aoutput, the sum of the columns of the TripArray matrix. For each iteration, we save C as Cprevious, causing our calculation of Anew to be updated. Then we copy the values from Anew and use them as the new Ainput . We do this procedure over and over again until the error between Cprevious and our desired attraction array is less than 1%.
Our calculated TripArrays for each of the 6 trip types can be found in our Excel file.
Cumulative Trip Distributions:
Below is given the table of the number of one-way trips for each mile range of Miles Per Trip. The Number of Trips is shown for each of the 6 trip categories, as well as the cumulative distribution.
The number 977,729 is the total number of trips per day in our city. Dividing this by our population of 250,000, we see that the average citizen takes 3.91 one-way trips per day.
Below is the trip distribution for each of the 6 types of trips:
Below is the trip distribution for each of the 3 types of Home-Based trips:
PersonTripLength Distribution Analysis:
Home-Based Work:
Home-Based School:
Home-Based Recreation:
These are the PersonTripLength distribution for HB-Recreation for both one-way trips and round trips. It makes sense that this distribution would be heavily skewed to the right (even more so than HB-Work and HB-School) because people have a lot of discretion over where they choose to go for recreation time. People are going to choose recreation zones that are near their homes, minimizing Miles Per Trip. Because our recreation zones (retail, restaurant, open space, zoo, theater district and stadium, and libraries) are spread out fairly evenly throughout the city, people can easily travel to a nearby recreational area.
Recreation-Based Recreation:
This is the PersonTripLength distribution for RB-Recreation for one-way trips. RB-Recreation trips only make sense as one-way trips because people would never (or very rarely intentionally) travel from one store/park to another and then back to the original store/park, so the notion of round trips does not really hold. The distribution shows a bias for intrazonal trips, that is trips between two locations within one zone. In order to correct for this effect, we decreased the friction factors (equivalently, increased the distances) of the intrazonal trips that represented recreational zones. We decreased the proper diagonal entries on the F matrix by a factor of 10 to represent the fact that if two stores within the same store are quite close, we should not count the distance between them as worthy of a “trip” because a person can easily walk between two stores in the same shopping center, for instance. The altering of the F matrix helped to mitigate the bias toward intrazonal trips, but it in no way eliminated it. The remaining bias can be justified because we feel that many people would consider a trip of just less than .5 miles to be significant and worthy of using a means of transportation other than by foot. Thus, the distribution is heavily skewed to the right, as people who are already at a recreational zone would likely try to stay in that zone when traveling to their next desired recreational destination, if at all possible.
School-Based Recreation Trips:
This is the PersonTripLength distribution for SB-Recreation for one-way trips. Like RB-Recreation trips, SB-Recreation trips only make sense as one-way trips because students would never (or rarely intentionally) leave school, head to a recreational area, then go back to school, so the notion of round trips does not really hold. It makes sense that this distribution would be heavily skewed to the right because students have a lot of discretion over where they choose to go for recreation time. Students are going to choose recreation zones that are near their schools, minimizing Miles Per Trip. Because our recreation zones and our schools are fairly evenly distributed throughout the city, students can easily find a recreational zone that is near their school to travel to.
Work-Based Recreation Trips: