ADDING HIGH-SPEED & COMMUTER RAIL TO A SHORT LINE RR

Hamid Qaasim

Sound Transit

Seattle, WA

Vivian Papen

Sound Transit

Seattle, WA

Todd Popelka

Sound Transit

Seattle, WA

Carol Doering

Sound Transit

Seattle, WA

ABSTRACT

Many existing freight train alignments have been

abandoned or seldom used. As communities grow, these

abandoned short line railroads sometimes provide

economical solutions to obtaining new right-of-way for

expanding commuter rail service. Regional transit

authorities have purchased these short line railroads for

extending their existing passenger services to more

communities along their alignments. Although this

strategy provides considerable savings in time and money

for development of a rail corridor, there may still be

significant challenges involved with upgrading old

alignments to current regulations and higher classes of

service. A successful line extension requires close

cooperation between the regional transit authority, the

Federal Railroad Administration (FRA), local

jurisdictions, businesses, and community organizations

along the alignment to understand and address concerns

of the stakeholders. This paper will discuss how Sound

Transit converted abandoned freight lines into an

extension of its commuter rail system that will soon bring

high-speed rail to Washington. In it we will discuss the

aspects of community partnerships, design challenges,

safety certification, construction, and service delivery for

a commuter rail extension.

BACKGROUND

As gasoline prices continue to rise, the public

becomes more interested in mass transit and transit

districts search for ways to economically move more

people. Some regional transit districts have found that

existing or abandoned freight rail corridors are viable

solutions for new commuter rail line extensions. With

freeways getting more crowded, an increasing number of

drivers are converting to becoming train riders because

commuter rail service can provide a reasonable travel

time in safety and comfort. Additionally, many rail

systems now offer special trains for games and other

weekend events, which further promote ridership and

customer loyalty.

There are many abandoned or underutilized freight

rail alignments available in North America, which can be

upgraded to meet the needs of today’s commuter. As the

ridership demands on public increase, many transit

agencies are considering purchasing these freight rail

alignments. This paper will discuss the design

development, safety, and construction issues that Sound

Transit faced as it converted an underutilized freight rail

alignment into a busy commuter rail extension that will

soon double as of the nation’s high-speed rail corridors.

Figure 1 shows the alignment of the Sound Transit

Sounder Commuter Rail System which consisted of 73

miles of track running from the city of Everett, 34 miles

north of Seattle to Tacoma, 39 miles south of Seattle. The

extension added 8 miles of track going south from

Tacoma to the city of Lakewood and 11.5 miles of

abandoned track going south from Lakewood to Du Pont

that will bring high-speed rail online in Washington in

2016.

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Figure 1: Sound Transit Commuter Rail System

Sound Transit acquired 18.25 miles of Class 2 freight

tracks where 15 miles were being used as a local short

line spur with the rest either abandoned or in a state of

disrepair. This track had to be brought into compliance

with FRA requirements1. A capital construction program

was implemented to convert this track to Class 5 for use

as a commuter rail line that will also carry high-speed rail.

Although acquiring railroad right-of-way, permits, and

municipal requirements provided financial and schedule

challenges, the civil alignment issues proved to be just as

daunting. There was one short line spur connected to the

southern end of the existing commuter rail line, but it had

1 U.S. Department of Transportation – Federal Railroad Administration

– Office of Safety, April 2009, Code of Federal Regulations – Title 49,

Track Safety Standards – Part 213, Subpart A to F Class of Track 1-5

Includes Defect Codes. Omaha, New England: The Rail Education Bureau

to be connected to another freight line that was a few city

blocks away. This required obtaining right-of-way and

building a connector to link the two different freight lines.

There were city intersections to cross and substantial

grade changes to navigate. As design progressed, it

became apparent that linking these two lines might

require grades of 4 to 5% to make up the elevation

differences. One of the design concepts called for an at-

grade crossing through a busy city intersection

immediately after a 3 to 4% slope while another required

lowering a busy street intersection and construction a

bridge over that intersection. You will find the solutions

to these problems in the design and construction sections

of this paper.

BUSINESS, COMMUNITY, &

GOVERNMENT COLLABORATION

A successful transit system relies on timely reliable

service that builds ridership and customer loyalty.

Developing strong bonds with the community and

businesses fosters the relationships that are so essential

for support of a major transportation capital improvement

program. This collaboration is one of the most important

elements of a successful partnership for a safe,

convenient, and user-friendly transit system. The local

community had endured abandoned sections of track and

under-utilized track for years and they wanted to do

something about this attractive nuisance. It was an

eyesore that also presented a safety and security hazard to

the community. Sound Transit had established a

relationship with the local governments, business, and

community groups, through implementation of regional

bus service, commuter rail, and light rail in this

metropolitan area. We met with government, business,

and community groups to see how we could all work

together to improve the quality of life for all of the

stakeholders.

The short line spur had only a few trains a week that

served local small manufacturers and warehouses and

extending the commuter rail service would have a

substantial impact on traffic and safety. We had to work

very closely with the public and the local businesses to

ensure that we minimized the impacts to freight service

and commuter traffic. We had to be particularly sensitive

to the needs for the local businesses to continue to run

freight on these tracks.

At Sound Transit community is a high value and we

held several meetings with the community, businesses,

and the cities during the planning phase to identify the

most significant concerns and we developed working

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groups to address those concerns as a community of

stakeholders. We are extremely proud of our outreach

program and we are very focused on the idea that we are

all one community. Tacoma Washington is the largest

city in this particular line extension and it has an

extension campus of the University of Washington in its

downtown area. In addition to the needs of the university

community, we also had to work with several businesses

that ship and receive materials by rail car on a frequent

and regular basis. The university and these businesses are

vital parts of this community and we wanted to ensure

that we worked with these stakeholders on a

transportation plan that was good for all of us. During the

environmental assessment phase we worked very

carefully to identify any impact of significance so that we

could develop meaningful mitigation plans. We studied

traffic patterns, bicycle routes, and pedestrian pathways to

identify street, sidewalk, or right-of-way impacts in our

Environmental Impact Study (EIS).

We evaluated all of the information collected to

produce an EIS and a design criterion that would

incorporate answers to all of the significant concerns and

needs of these stakeholders. Building public support is a

matter of confidence and transparency gained through

honest collaboration between the transit agency, the

community, businesses and the cities. This collaboration

helped us to design a safe, convenient, and customer

based transit system that serves the community.

TRANSIT SYSTEM DESIGN

Commuter and freight railroads are regulated by the

Federal Railroad Administration (FRA) and the transit

authority must comply with a series of FRA regulations to

implement a new commuter rail service or line extension.

Additionally the Federal Transit Administration (FTA)

provides funding for commuter rail cars and equipment

which means that a commuter rail agency must comply

with regulations from both

As the new line traverses through the old alignment,

trains will travel at much higher speeds and frequencies

than before. Sound Transit worked with local

jurisdictions to plan grade crossing, signalization, and

community outreach. Intersections were equipped with a

combination of pre-emption, channelization, and other

warning devices for crossing safety. The geometry of the

alignment is one of the most important aspects of the

design as it must provide grades that the locomotive can

reliably navigate while crossing intersecting roadways in

a manner that provides for pedestrian and vehicular

safety.

During design development an alignment was

considered that would have a significant stretch of 5%

grades and a skewed crossing at a major intersection.

Concerns were raised about the grades since most

passenger rail grades generally do not exceed 3% and

there are only a few places in the country where diesel

locomotives are subject to such grades. Sound Transit

conducted live brake tests on a nearby short line freight

spur to evaluate braking characteristics on a 5% grade in a

variety of conditions. A consist of four commuter rail

cars and a locomotive were brought up the slope and

stopped. Brake systems on the cars were verified to be

acceptable for service according to FRA requirements23

.

Tests were conducted that evaluated the ability of the

locomotives to start from a dead stop going uphill on the

5% slope in dry, moist, and wet conditions. Of particular

interest was the ability of the locomotive to start on an

uphill grade with leaves on the track. The tests also

evaluated braking ability of the consist on a 5%

downgrade.

Computer models were also run to forecast

locomotive performance and a hazard analysis was

performed to evaluate stopping ability on the 5%

downgrade from 45 mph. The combination of live dead

start tests, computer modeling, and hazard analysis of

crossing safety at the skewed intersection led to

examining a new alignment that would result in lowering

a busy street and constructing a track bridge. Although

significantly more expensive, this alignment proved to be

safer and it provided more reliable performance. Once

selected, the alignment design included a CTC signaling

and communication system to provide a constant warning

signalization for grade crossings. Signage, pre-emption,

crossing gates, bells, and wayside horns were all

incorporated into the design for crossing safety.

2 U.S. Department of Transportation – Federal Railroad Administration

– Office of Safety, June 2002. Code of Federal Regulations – Title 49, Railroad Locomotive Safety Standards – Part 229, Omaha, New

England: The Rail Educational Bureau 3 U.S. Department of Transportation – Federal Railroad Administration

– Office of Safety, April 2002. Code of Federal Regulations – Title 49,

Brake System Safety Standards for Freight and Other Non-Passenger

Trains and Equipment, End of Train Devices – Part 232,Subpart B. Omaha, New England: The Rail Educational Bureau

2

CROSSING SAFETY & CERTIFICATION

Sound Transit has a robust safety certification

program456

that provides procedures to implement and

confirm conformance to FRA system safety requirements.

We conducted public meetings along with field surveys of

business along the alignment to gather data on risks and

potential safety hazards to create a baseline for the

Preliminary Hazard Analysis (PHA). Field surveys

included collecting traffic data, reviewing the literature

for accidents, traffic counts, and observation of pedestrian

travel patterns. These field surveys also included video of

peak hour traffic patterns that were correlated with the

proposed commuter train schedule to assure that all

impacts were adequately considered. The alignment goes

through an area near Joint Base Lewis-McCord where

many military families live. This required additional

safety outreach to address the transient nature of military

families with children moving into the area.

Road geometry at each grade crossing was upgraded

to accommodate traffic and pedestrian pattern. This area

had collector streets that ran parallel to the rail corridor on

both sides. These streets were only about 200 away from

the track right-of-way and presented unique challenges to

design of the signaling system for preemption and

crossing gate timing. They also required close

coordination with the city traffic system to avoid

significant traffic jams in these areas. The previous short-

line usage had an occasional locomotive pick up a few

cars a couple of times a week at 15 to 25 mph. The

commuter rail line runs seven trains a day eastbound and

westbound during the peak period at up to 70 mph.

The significantly increase frequency of train

operation noticeably impacts the area and special grade

crossing analysis7 were performed and presented to the

FRA to certify each crossing. These analyses calculated

the probability of auto-train collisions and confirmed that

the crossings were safe from accidents induced by the

new commuter line. They considered the road geometry,

probability of a driver or pedestrian going around the

grade crossing warning gate arm, and the impact of the

parallel streets that were on either side of the trackway.

4 Department of Defense, Defense standard MIL-STD-882E,

Department of Defense Standard Practice - System Safety, 11 May 2012 5 Sound Transit, Agency System Safety Program Plan for Design and

Construction, September 2010 6 Sound Transit, Agency Safety and Security Certification Plan (Design

and Construction), September 2010 7 Sound Transit, Sounder commuter Rail Tacoma to Lakewood Rail

crossing Summary and Hazard Analysis, September 2012

Raised curb channelization and quad-gate arms were

installed in some areas to reduce the chance of drivers

going around the gate arms. This equipment was

synchronized with local traffic signals to provide either

pre-emption or advanced pre-emption for clearing the

high-way grade crossing intersection before a grade

crossing is activated or a train arrives at an intersection

During commissioning Sound Transit confirmed the

Warning Time (WT), Advance Pre-emption Time (APT),

Gate-Down Time of each grade crossing system and the

interfaces with adjacent traffic systems at varying design

speeds. The safety certification program provided for

verification of all warning times and for confirmation that

the constructed facilities met the design criteria for safety

prior to revenue service.

The safety certification program also included

validating and verifying that the alignment were designed

and built according to FRA regulation and safety-related

design criteria as shown in Figure 2. Hazard analysis and

vulnerability assessments were performed to ensure that

all possible hazards were mitigated by either engineering

design or operation rules and procedures. Due to the

staggered construction programs, safety certification had

to include letters of design conformance from the

engineer-of-record for two stations and trackwork that

was constructed two years before beginning the final

construction project. The designer and contractor for the

last section of the signal and trackwork project completed

both design and specification conformance checklists

during the final construction phase.

Operation, maintenance, and emergency responder

training are included in the safety certification program.

Train engineers, conductors, and maintainers were all

trained according to FRA regulations to ensure that they

were familiar with the new alignment. Sound Transit

worked with Amtrak, Washington State Department of

Transportation (WSDOT), and Burlington Northern Santa

Fe (BNSF) to provide an emergency responder training

which covered all aspects of passenger safety and train

operation. A “Hands-on” walk through was also

organized for the emergency responders to physically

examine all of the emergency equipment on the train and

the egress location for possible passenger evacuation.

During system integration, Radio and

Communication Coverage, ROW /Dynamic Envelope,

Train / Track Ride Quality, Rail isolation, Control Center

Interface, Signal Aspect / Sighting, Wayside Sign/

Marker/ Verification/ Visibility, and Grade /Pedestrian

Crossing / Intersection Interface were tested. All of the

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equipment was fine-tuned to confirm that all the systems

were working according to the design. All the necessary

data8 for safety certification was transmitted to the FRA

to verify that all safety certification processes were

performed and any potential hazards were mitigated by

design or O&M training and operations procedures. These

items were validated in the Specification Conformance

Checklist as shown in Figure 3.

8 Sound Transit, Sounder Commuter Rail Lakewood Extension Safety

Certification Verification Report, October 2012

Figure 2: Example of Criteria Conformance Checklist 9

Sound Transit is one of the few agencies that have automated safety certification and our software is called “SafetyLink.

9 Sound Transit, Safety Link – Safety Certification Database

2

Figure 3: Example of Specification Conformance Checklist 10

10

Sound Transit, Safety Link – Safety Certification Database

CONSTRUCTION STAGING

Having overcome the substantial design challenges,

now it was time to undertake the capital construction

program, which had to be built in phases. The

construction program was divided into several segments.

The Lakewood Commuter Rail Station and Parking

Garage were constructed at the south end of the new line

extension. The Lakewood Layover Yard was constructed

north of the Lakewood Station. The South Tacoma

Commuter Rail Station included the station and

associated trackway improvements for that segment. The

D to M segment included the lowering of Pacific Place, a

track bridge, and track connecting to the south end of the

existing commuter rail line at the Tacoma Dome

Commuter Rail Station. These locations are shown in

Figure 4 to orient the reader to the construction project.

Several of these sections had construction-related issues

that presented challenges to the safety team during

construction and for safety certifying the system.

Figure 4: Sounder Commuter Rail in Pierce County

At the existing end of the line station at Tacoma

Dome, the train stops just north of a busy intersection

where gates were timed to go down and then release

because the train did not proceed any further south from

that point. To initiate service south required setting the

gates to stay down until the train proceeded south through

the intersection to the next stop. Although this is not

novel in itself, the short city blocks required crossings at

multiple intersections to go down within a very close

sequence creating challenges for both noise from the

wayside crossing bells and horns as well as extended

traffic delays for both northbound and southbound. These

constraints were resolved through close coordination with

Safety, Operations, and Engineering to fine tune the

signals and crossing gate timing. Additionally,

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directional wayside horns were installed to mitigate noise

complaints.

The lowered street and track bridge were constructed

about 758 feet south of the existing end of the line station

at the Tacoma Dome Station. This area had significantly

more organic material that originally thought. During

construction, several rebar cages with #11 bars had to be

lengthened with special couplers when the initial drilling

for the caisson did not reach sufficient bearing at the

design elevation. Not only were there inherent delays, the

safety department had to be intimately involved in the

pre-planning and installation inspection of each caisson

after a 130’ rebar cage was dropped and toppled a crane.

Figure 5 shows the completed track bridge, where the

structure was lowered.

Figure 5: Completed Track Bridge

Another source of concern for this segment was a

location where historically people travelled down a

hillside to reach a sizeable mission that fed and sheltered

the homeless.

Figure 6 shows the Right of Way under construction

for the connectors between the two freight lines that are

being upgraded. The new connector track section bisected

this route as it ran parallel to the rear of the mission

campus. Construction for the connector track corridor

and lowering of the street is shown in Figure 7. This was

compounded by the fact that the hillside was steep and

required constant dewatering. We had to acquire

sufficient real estate to install fencing, sound walls,

dewatering, and retaining walls along several hundred feet

of that section. Near that location, we had to install

extended pedestrian crossing gates to accommodate the

extra wide sidewalks that were installed specifically for

bicycles and wheelchairs.

Figure 6: Right of Way Construction

Figure 7: Track Bridge Under Construction

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The project was also plagued by an artesian well and

excessive ground water from a few localized areas. In the

past the area was used to collect and distribute drinking

water to the adjacent communities. During construction

some of these structures that were acting as a cap for the

water supply were unearthed and posed a serious drainage

issue to the adjacent rail track bedding and ballast. Storm

infrastructure was redesigned to convey this large amount

of water downstream away from the track.

One section of the corridor traverses through a

superfund site, which requires special permits or waivers

for excavation, handling, and disposal of disturbed soil

that might be contaminated. Specific training in hazardous

material handling was required for individuals who might

be required to handle these materials. Finally, the layover

yard had to be constructed between the newly installed

trackway during revenue operations hours. In summary,

the construction team overcame some significant

challenges that included control of artesian water,

lowering a street, installing caissons through thick layers

of organic material, lifting 140’ rebar cages, extending

pedestrian crossing arms, constructing through a

superfund site, and constructing between an operating

railroad.

INTEGRATING COMMUTER AND HIGH

SPEED RAIL

Sounder Lakewood Extensions was part of the

WSDOT High Speed Rail Project. After the commuter

train services were extended to Lakewood, WSDOT was

working closely with ST to plan, design, and built the Pt.

Defiance Bypass Project. The existing passenger services

require slowing down due to curves and single-track on

the Freight main line tracks. The Pt. Defiance Bypass

Project will be running along I-5, which can reduce the

time for the passenger services and maintain the train

speed.

WSDOT organized a Technical Advisory Group

which is composed with all the cities along the alignment,

Pierce County, Military bases, school district and ST. The

Technical Advisory helps to identify and review the

design that possible be the locally preferred option,

minimize adverse project effects and identifying any

possible mitigation measures which are locally preferred.

The Technical Advisory Group brings different agencies

to address any potential concerns and will be able to

reduce the time for any design review.

Since High Speed Rail will share the same corridor

with the Commuter Rail, WSDOT has been

communicating with ST to review the alignment, possible

emergency evacuation location, system (grade crossing,

fencing, etc.) design, and community rail safety outreach.

In addition, ST was able to share any challenges during

the commuter rail extended to Lakewood. WSDOT and

ST are planning to perform hazard analysis jointly to

identify any possible hazards along the alignment, which

may be only for some specific location along the

alignment. The hazard analysis workshop will be

including all jurisdictions along the alignment to ensure

all possible hazardous situations and concerns are

mitigated by design or operation procedures.

WSDOT has already been working with the local

cities to review the traffic pattern and volume to consider

the possible grade crossing design. If necessary, at-grade

crossing may be eliminated to provide a safe and

exclusive Right of Way (ROW) for the high speed rail.

While the freight line alignment has been for a period of

time, WSDOT and ST will be required to establish an

intensive rail safety community outreach program to

communicate with the business and community along the

alignment about rail safety.

Sounder Lakewood Extensions was part of the

WSDOT High Speed Rail Project. After the commuter

train services were extended to Lakewood, WSDOT has

worked closely with ST to plan, design, and built the Pt.

Defiance Bypass Project.

Prior High Speed Rail is opening to the public for

revenue service, the High Speed Rail Authority

(WSDOT), the Commuter Rail Authority (ST), and the

Operating Railroad (BNSF) plan to model the Commuter

and High Speed Rail Schedule to confirm the train

schedule, and mitigation of route conflicts. All existing

grade crossings have been accepted by the local

jurisdictions before High Speed Rail was considered to be

implemented along the alignment. The High Speed Rail

Authority will work with ST to re-certify all the grade

crossings with higher train speeds to confirm that all the

warning equipment is activated with the adequate warning

time to the public.

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MAINTAINING LOCAL SHORT-LINE

SERVICE

Short-Line Railroad alignment has been servicing the

community before the commuter rail service and high

speed rail services are added. Generally, Commuter

service runs during the morning and the afternoon peak

hours for the community to travel for work and the high

speed rail will be running after and before the commuter

service. Since the Commuter and high speed rail services

are added to the Short-Line, the freight train (Short-Line

Service) and scenic railroad service require working with

the central dispatcher to ensure safe operation.

Operating procedures for the both Short-Line Service

and scenic railroad were updated and reviewed with ST

and WSDOT to ensure the interfaces with the Commuter

and high speed rail services are not affected. In addition

to updating the operating procedures, ST, WSDOT,

BNSF, Short-Line Rail Company, and the Scenic

Railroad Service reviewed the daily operating routine and

discussed any potential hazards when the commuter rail

and high speed rail are operating on the Mainline.

DELIVERING THE DREAM (OPENING)

The union of construction and operation plans come

together to deliver the dream of opening a new rail service

to a community. Approximately six months prior to an

opening date a team of people meet regularly, bi-weekly

and then weekly to address any gaps in construction

activities, develop a communication plan, exchange

information on key audience feedback from the

stakeholders. The goals of these meetings were to

strategize and develop appropriate activities that celebrate

and appreciate the local community members who have

shared in all phases of the project. Knowing the culture

and habits of a community is key to scheduling a

successful opening day celebration. For instance, you

would not want to schedule an opening for a Sunday

morning in a community that has a firm commitment to

attend Sunday religious services.

Sound Transit produced “Zoomin’ through the Sound” as

its rail safety video to introduce this new commuter line to

the community. It can be found on our safety website at

http://www.besmartbesafe.org or on YouTube at

http://www.youtube.com/watch?v=yAjs_2LJ3ec

The video was recognized by the Mercury Awards

with an Honor award in the Public Service Campaign

category. The Mercury Awards is an international award

program with awards for all communication fields. A

popular Seattle hip-hop group, the Blue Scholars

partnered with Sound Transit to deliver train track safety

messages in an unexpected and authentic way. The

messages were delivered in a contemporary artistic form

to capture the ear of a current audience. These messages

address the hazards of using headphones as a risk to not

hearing the train bells and horns and to be smart around

the tracks by staying behind the yellow line on the

platform and not trespassing on the tracks. The video has

been well received having over 130,000 viewers since its

release in October 2012.

Since trains had not run in this corridor for many

years, an adjustment period was needed for residents to

become aware of the new service. Communities were

educated about rail safety habits. An educational

campaign began approximately 12 months prior to the

anticipated service. The goal of the campaign was to

teach the public about hazards and desired behaviors

when driving and walking around tracks and trains. Staff

met with all stakeholders, i.e., civic organizations,

community leaders, business owners, city officials and

local law enforcement to get a sense of where people

gather, their travel patterns and the existing resources for

shared communication. Based on what is learned, a

strategic work plan is developed to guide the

implementation phase of the safety education plan.

During the opening week, street teams of staff,

volunteers, police, and paid support were out in force to

provide advertising, train schedules, answer questions,

and collect any information necessary to improve the

customer experience. Adding a new commuter rail line

extension involved almost every department of the transit

agency and each phase presented its own collection of

unique challenges. We hope that this paper has provided

you with a glimpse into the organizational challenges that

are faced by a rail transit agency when converting an

abandoned freight line to commuter rail service.

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REFERENCES

Sound Transit, Sounder Commuter Rail Lakewood

Extension Safety Certification Verification Report,

October 2012

Sound Transit, Sounder commuter Rail Tacoma to

Lakewood Rail crossing Summary and Hazard Analysis,

September 2012

Sound Transit, Safety Link – Safety Certification

Database

U.S. Department of Transportation – Federal Railroad

Administration – Office of Safety, April 2009, Code of

Federal Regulations – Title 49, Track Safety Standards –

Part 213, Subpart A to F Class of Track 1-5 Includes

Defect Codes. Omaha, New England: The Rail Education

Bureau

U.S. Department of Transportation – Federal Railroad

Administration – Office of Safety, April 2002. Code of

Federal Regulations – Title 49, Brake System Safety

Standards for Freight and Other Non-Passenger Trains

and Equipment, End of Train Devices – Part 232,Subpart

B. Omaha, New England: The Rail Educational Bureau

U.S. Department of Transportation – Federal Railroad

Administration – Office of Safety, June 2002. Code of

Federal Regulations – Title 49, Railroad Locomotive

Safety Standards – Part 229, Omaha, New England: The

Rail Educational Bureau

Sound Transit, Agency System Safety Program Plan for

Design and Construction, September 2010

Sound Transit, Agency Safety and Security Certification

Plan (Design and Construction), September 2010

Department of Defense, Defense standard MIL-STD-

882E, Department of Defense Standard Practice - System

Safety, 11 May 2012