Chapter 3 -Line-Based Analysis-edited-final

1
Chapter 3: Line Based Analysis
Introduction and Problem Definition
In the decision of where to locate a facility, it is important to consider
transportation networks and other infrastructure, for instance, pipeline networks. The
requirements for the facility may then be constrained to specific points or intersections,
with few locations meeting the needs criteria of that particular new business.
Companies that seek to minimize their transportation costs are therefore
very careful to build delivery centers in the right location. FedEx serves as a model of a
business that strives for efficient transportation of goods while minimizing these costs.
Their practice is to have regional warehouses that serve as distribution centers to collect
and sort packages. The packages destined for delivery to customers in the east side of
Seattle are received at the warehouse located in Issaquah while those packages destined
for South King County are received at the warehouse located in Fife, thus, minimizing
travel time and reducing costs.
When new development expands into areas with existing transmission
pipelines, there is a need for regulations to minimize potential conflicts between pipelines
and development. Federal and state regulations attempt to ensure pipeline safety by
regulating the design, operation and maintenance of pipelines. However, local
government has the authority to implement land use regulations to minimize the
likelihood of accidental damage to pipelines from construction activities. Pipeline

2
damage or failure could potentially result in the risk of injury to both general and
vulnerable populations, as well as, to important emergency facilities. That is the case of
Renton docket 78-planning near pipelines that required the GIS analyst to take into
consideration the Municipal Research and Services Center of Washington (MRSC) model
setback ordinance for a transmission pipeline. 1
The application of the model required the acquisition of current data in a
shapefile or feature class format followed by the geoprocessing of a 50-foot or 500 foot
buffer setback measured from the edge of hazardous liquid, gas pipelines and most
structures. For highly populated facilities - especially those with vulnerable populations,
such as, schools, hospitals, arenas, day care centers, and emergency services - the
analysis required the geoprocessing of a buffer of a 500-foot setback from the edge of the
pipeline so the resulting change in the Municipal Code of the City of Renton balanced the
need for public safety through promotion of careful development near pipelines to reduce
the likelihood of damage to such facilities. The goal was also to avoid needlessly
complicating development regulations or becoming too onerous for applicants seeking
permits. Thus, these code changes fulfill MRSC requirements and protect public health,
safety and welfare and are consistent with the Growth Management Act, King County
1
Model Setback Ordinance for Transmission Pipelines. http://www.mrsc.org/subjects/pubsafe/pipesetbackord.aspx
1/6/2012

3
planning policies, and the City of Renton Comprehensive Plan. Figure 3.1 below shows
a map that features the 500-foot buffer measured from the pipeline network that intersects
existing schools, and hospitals and thus indicates constraints for any future development
along the pipeline path.
Figure 3.1 Docket #78 - Planning Near Hazardous Pipelines Map

4
Figure 3.2 Legend Hazardous Pipeline Map
The location selection for a linear-based facility must take into
consideration various factors. An example of GIS analysis that takes into consideration
associated data along a line is the selection of alternative routes for public transportation.
Factors requiring consideration include: zoning restrictions, land use regulations, public
population to be served along the route, and even natural obstacles such as rivers or cliffs.
Locating the best transportation route often involves public participation, public review,
and interaction of interest groups.
An illustration of choosing a network is the Metro King County proposal
to add a new bus route known as Rapid Ride F Line to operate between Burien, SeaTac,
Tukwila and Renton starting in fall 2013. King County Metro expects to place in service,
“eye-catching red and yellow buses that will pull up and stop every 10 to 15 minutes,
seven days a week which will generate a fastest and easiest line to travel. The stations
will have electronic signs showing when the next bus will arrive and will allow ORCA
card readers to pay before boarding the bus. Stations and stops will be placed where most

5
riders gather, at easy walking distance. The buses will have low floor for easy boarding,
free Wi-Fi, and security features. As buses approach intersections, they will send signals
to traffic lights that will hold green lights longer or switch red lights to green faster to
improve the time of the ride.”2
Metro is considering several different routing options for
the F line as it travels between Burien and Renton. The path between Burien and Tukwila
train station has been set. However, after Rapid Ride F bus leaves Tukwila train station,
there are three alternative routing options. A closer look to the inset shown as figure 3.5
depicts the three alternative routes from the Tukwila Station to South Renton Park and
Ride. They are options A, B, and C. King County Metro has also proposed two
alternative routes from the South Renton Park and Ride to the Landing shopping area
across from the Boeing 737 plant. Figure 3.6 and 3.7 are showing the proposed extension
to the Landing known as Option A–Landing and Option B-Landing. The three options
from the Tukwila Station (A, B and C) combined with two proposed extensions to the
Landing shopping area have generated six possible routes. The stops are yet to be
determined and they will be based on the surveys to prospective bus-riders. Nonetheless,
consensus has been reached for the path between Burien and Tukwila and the Tukwila
train station. During the decision process, King County Metro conducted online surveys
2
King County Metro website: http://www.kingcounty.gov/transportation/kcdot/MetroTransit/RapidRide/FLine.aspx
12/5/2011

6
in English and Spanish and an open-house at Renton City Hall on January 26, 2012. 3
The
results of the public participation have not yet been made public. The decision-making
team conjoined by King County Metro and Renton’s transportation Division will assess
the results from the survey as well as the GIS analysis results provided by the City of
Renton Planning Division. One of the fundamentals for the Landing extension is the
number of full-time employees that could be served along each alternative route.
Figure 3.3 King County Metro Map – RapidRide F Line proposed routing and stops
3
Public involvement, take an online survey. http://www.surveymk.com/s/RapidRideFLineRouting 1/22/2012

7
Figure 3.4 Map Legend Figure 3.5 Routing Options A, B and C
Fig 3.6 Proposed Extension Option A (along Logan Ave N) and Proposed Extension B (Along Park Ave)

8
Modeling Representation: GIS Analysis
In building the model to help the selection of the best route, the analyst
used Model Builder. Model builder within the toolbox of ArcGIS Desktop Version 10,
ESRI software, is an application that allows the creation, editing and management of
models in order to evaluate different options. The model is then saved and repeated for
analysis of each combination of routes.
The following describes the steps used to graphically depict the six
alternative routing options for the King County Metro proposal for the Rapid Ride F line.
The analyst mapped each route presented in figure 3.5 as options A, B and C with the two
proposed routes to the Landing shopping area shown in figure 3.6. The two latter routes
are designated as Landing A which passes along Logan Ave N and Landing B which runs
along Park Ave. To build the GIS model, the analyst used the ESRI model builder tool
described in the steps below. The final table shows the results of the analysis delivered to
Metro King County and Renton’s transportation division for further evaluation.
1. Merge the routing options (A, B and C) to the proposed extension options to the
Landing shopping area (Extension A-Landing and Extension B-Landing).
a. Option A merged to extension to the Landing A
b. Option A merged to extension to the Landing B
c. Option B merged to extension to the Landing A
d. Option B merged to extension to the Landing B

9
e. Option C merged to extension to the Landing A
f. Option C merged to extension to the Landing B
Fig 3.7 Feature class showing Option C to South Renton Park and Ride merged to Option B proposed extension
to the Landing along Park Ave.
2. Use the geoprocessing tool to trace a 0.25 mile buffer for each itinerary.

10
3.8 Snapshot of geoprocessing buffer tool with 0.25 mile distance
3. Add the 0.25 mile buffer to the map. Each route option depicts a slightly different
buffer, because it measures the buffer from a different combination of routes. The
following steps below show the graphic representation of the combination of Option
C for the RapidRide F Line along with the proposed Extension B to the Landing.

11
3.9 Screen snapshot showing extend of the buffer and location of light rail station, park and ride parking lots,
and Tukwila train station
4. Select all of the business licenses within the boundary of the 0.25 mile buffer.

12
5. Export all of the selected businesses located inside of the buffer and save the
output as a new feature class.

13
3.10 Table showing business name, national industry code, and total of full time employees (FTE) field per
business license
6. Then look for the field that represents the total of full time employees per
business license. Sum the total number of full time employees per routing option
and save as a new output.
7. Add the database file to the table of content (left side of the screen) so that it
appears on the map and within the map legend. Insert the legend to reflect the
results and save the map as a pdf file.

14
3.11 Export final map as pdf file
The table below shows the projected ridership of full-time employees per
route combination. Option C combined with extension B to the Landing shows the
highest potential ridership of the six proposed route options.
OPTION EXTENSION NUMBER OF
FULL TIME EMPLOYEES
Option A Extension A 23.451
Option A Extension B 25,414
Option B Extension A 24,661
Option B Extension B 25,866
Option C Extension A 26,411
Option C Extension B 27,871
Figure 3.12 Table showing number of full time employees per combination of routes

15
GIS-Science
The two case examples presented in this chapter, the development
restrictions along Renton pipeline network and the proposed RapidRide F line in the City
of Renton, involve corridor routing which reflects the problem of continuous space siting.
In Location Analysis and GIS, Church and Murray explain that “often the approach taken
is to transform a problem from a field view of geographic space to a discrete, network
representation.” Consequently, “considerable work involves defining the network and
deriving attributes associated with the network. GIS and associated functionality is
essential in this process.” 4
They also suggest that the selection of the best route or
corridor can be accomplished by following below analytical steps:
1. Decide what data is the most meaningful in terms of routing, and
collect the data for the analysis. Select the most suitable GIS layers. The most meaningful
components include gathering appropriate data to support the routing of the corridor with
layers that can influence the outcome such as:
i. Topography and Slopes (maybe the words ‘slopes’ is adequate, you
choose)
ii. Land use designation (residential, industrial, commercial)
4
Ibid 2, 167

16
iii. Presence of significant buildings (historic buildings, hospitals or
schools)
iv. Environmental constraints, such as, designation of Type 1
conservation areas (for rivers, lakes, and some creeks) which indicate
the presence of endangered species.
v. Transportation elements (existing roads, pipelines, transmission lines)
vi. Land ownership, geocoded addressed of business and/or taxpayers
2. Define a network of possible transitions across the landscape.
3. Utilize the appropriate model; to identify the route which meets the
desired criteria, e.g., least vehicular impact, lowest cost, or serves the highest amount of
employees along the corridor.
4. Analyze the data to compare the alternative routes or corridors.
All of the above steps are achievable with the extension ArcGIS Network
Analyst built into to ESRI software. This extension facilitates the following mapping
tasks to perform a network-based spatial analysis: routing, fleet routing, travel directions,
closest facility, service area, and location-allocation. When using the ArcGIS Network
Analyst extension, the analyst can dynamically model realistic network conditions,
including one-way streets, turn restrictions, speed limits, and variable travel speeds based

17
on traffic. Thus, an analyst can easily build networks from GIS data by using a
sophisticated network data model.” 5
The two examples detailed above did not require the use of this extension
due to routes that had already been pre-established, for the pipeline location and the
Metro King County bus routes. Nonetheless, the network analyst extension has valuable
uses as shown in online demonstrations on the ESRI website at
http://www.esri.com/software/arcgis/extensions/networkanalyst/key-features.html as well
as in Chapter 5 of this paper. The website provides examples of how to use this extension
for routing (multi-point routing, time window supported on stops and traveling
salesperson), vehicle routing problems (time windows, driver breaks, vehicle capacities
and order quantities as in FedEx delivery trucks), and service area 6
(in case of complex
polygon generation or allocation across networks).
The GIS analyst can now benefit from the features and capabilities of the
ArcGIS Network Analyst extension for analysis of network-based location allocation.
Examples include the following abilities:
a.) discover the shortest and most efficient routes for a fleet of vehicles
that travels to multiple destinations,
5
ESRI web page ArcGIS Network Analyst. Overview.
http://www.esri.com/software/arcgis/extensions/networkanalyst/index.html. 1/20/2012
6
ArcGIS Network Analyst Key Features. Service Areas: View Demo
http://www.esri.com/software/arcgis/extensions/networkanalyst/key-features.html

18
b.) establishment of time windows to schedule when vehicles should
arrive to a location; and
c.) determine optimal locations for multiple facilities.
The analyst is thus able to y perform a location-allocation analysis and
define service areas based on travel time or distance, create a network using existing GIS
data, and generate a matrix of network travel costs from each origin to all destinations.
Conclusion
In this chapter, I introduced the concept of location selection along a line
and/or network. It has been shown that the facility might be either a path or a corridor. In
underlying this problem, there is the assumption that a network of nodes and arcs exist, or
the path can be derived by connecting the starting location with the destination point. I
presented two cases of networks with associated data that have influenced the final
decision on regulating future development or in choosing the bus route to serve a greater
ridership based on the numbers of full-time employees. This chapter also discussed the
capabilities of network analyst, an extension of ArcGIS software. To show how this
extension tool can be used, I pointed the reader to online demonstrations on the ESRI
webpage which can address the following problems: vehicle routing, closest facility and
driving directions. The aim of this chapter was to illustrate important fundamentals on
line/ network location selection, and what GIS tools and extensions are available to
planners, developers and the GIS community.

Chapter 3 -Line-Based Analysis-edited-final

More Related Content

What's hot (20)

Similar to Chapter 3 -Line-Based Analysis-edited-final (20)

Chapter 3 -Line-Based Analysis-edited-final