Crystal City Basis of Design

7/31/2019 Crystal City Basis of Design

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Crystal City Streetcar ProjectConceptual Engineering Basis of Design

DRAFT

October 26, 2012

Prepared by URS Corporation


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Octpber 26, 2012 Crystal City Streetcar Project

DRAFT Conceptual Engineering Basis of Design

URS Corporation1

TABLE OF CONTENTS .............................................................................................................. 1

1.0 INTRODUCTION ......................................................................................................... 2

2.0 GENERAL ................................................................................................................... 2

2.1 Other Ongoing Projects ................................................................................................. 22.2 Streetcar Vehicle ........................................................................................................... 2

2.3 Alignment Geometry ..................................................................................................... 5

2.4 Design Speeds ................................................................................................................ 6

3.0 STREETCAR STOPS ...................................................................................................... 7

4.0 CIVIL ENGINEERING ASSUMPTIONS ............................................................................ 8

4.1 Cross Slope and Roadway Reconstruction .................................................................... 8

4.2 Lane Width .................................................................................................................... 9

4.3 Track Structure/Pavement Reconstruction ................................................................... 9

4.4 Special Trackwork ........................................................................................................ 11

4.5 Drainage ...................................................................................................................... 11

4.6 ADA Accessibility/Upgrades ........................................................................................ 11

4.7 Bicycle Facilities ........................................................................................................... 115.0 SYSTEMS ENGINEERING ASSUMPTIONS .................................................................... 12

5.1 Traction Power Supply System Requirements ............................................................ 12

5.2 OCS Infrastructure ....................................................................................................... 14

5.3 Streetcar Operational Control ..................................................................................... 15

5.4 Additional Systems Engineering Considerations ......................................................... 16

6.0 STREET LIGHTING ..................................................................................................... 16

7.0 UTILITIES ................................................................................................................. 17

7.1 Conflicts & Relocation Assumptions ............................................................................ 17

7.2 Areas of Importance .................................................................................................... 17

8.0 TRAFFIC ................................................................................................................... 17

8.1 Traffic Operations ........................................................................................................ 18

8.2 Traffic Signals ............................................................................................................... 188.3 Pavement Markings & Signage .................................................................................... 19

9.0 STRUCTURAL............................................................................................................ 19

10.0 SURVEY ................................................................................................................... 19

10.1 Survey Control ........................................................................................................... 19

10.2 Base Mapping ............................................................................................................ 19

10.3 Utility Field Mapping ................................................................................................. 19

10.4 Geotechnical Boring Locations .................................................................................. 20

11.0 MAINTENANCE AND STORAGE FACILITY ................................................................... 20


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1.0This report documents the proposed Basis of Design for conceptual and preliminary engineering

of the Crystal City Streetcar. Presented herein are basic design parameters and assumptions that

will form the basis of the civil, track, systems, structural, and utility engineering design effort.

The objective is to deliver a preliminary engineering package consistent with Arlington Countystandards and within the established project goals and budget. The criteria herein are

presented in an abbreviated form for higher level decision making. It is important that the

assumptions stated in this document be reviewed and concurrence obtained to avoid

miscommunication; an early consensus is also important to avoid impacts to the project design

cost and schedule. This Basis of Design has been developed using information received from the

County, from URSs experience with streetcar projects in urban environments similar to those

found in the project area, other similar projects in the area (such as the Crystal City Potomac

Yard Transitway, Columbia Pike Streetcar, and streetcar projects in the District of Columbia), and

using guidelines such as WMATAs Tram/LRT Guideline Design Criteria. This is intended to be a

living document upon entering advanced engineering efforts, the Basis of Design should be

developed further and reevaluated to ensure that it remains consistent with the project goals

and the Countys desires.

2.02.1 Other Ongoing ProjectsThere are other planned future projects that may impact the Crystal City Streetcar. It is

important to consider these projects when developing conceptual designs or evaluating

alternatives, as they could impact the feasibility and/or cost of this project. Provided below is a

list of known projects in the vicinity of the Crystal City Streetcar. Coordination with these

projects will be required during future phases of project development.

Crystal City Potomac Yard (CCPY) Transitway

Potomac Yard developments

Columbia Pike Streetcar

Pentagon City development between S. Eads St. and S. Fern St.

Crystal City street improvements (including Crystal Drive, and reconstruction of Clark

and Bell Streets)

Future redevelopment in Crystal City

2.2 Streetcar VehicleFor the Crystal City Streetcar, a modern streetcar vehicle will be used. The vehicle will becapable of operating in exclusive or semi-exclusive alignments, or in shared lanes with

automobiles. Articulated segments on the vehicle will allow it to negotiate the tight curves that

are common in urban environments. The vehicle will have the capability of being operated in

either direction, with a fully-equipped operators cab located at each end. The design will

accommodate only single-car vehicle consists. In some locations along the corridor, the ability

to extend the platform length to accommodate longer vehicle consists is limited because of right

of way availability or conflicts with existing features such as driveways.


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Assumed values for critical vehicle dimensions are shown in the table below. These values are

based on characteristics of streetcar vehicles that are currently available for procurement in

North America.

Table 2.1

Assumed Ranges of Critical Specifications

Specification Desirable Max Min

Turning Radius - - 82 feet (25m)

mainline; 66 ft (20m)

yard/storage track

Vehicle Width 8.0 feet (typical

streetcar)

8.7 feet (Std. LRV) -

Vehicle Length - 82 feet 66 feet

Boarding Height 14 inches - -

Percent Low Floor - 100% 50%

Wireless OperatingRange

2 miles - 1 mile

Vehicle Weight (at

crush load AW41)

- 141,200 Pounds (25m

vehicle)

-

Axle Loading (at crush

load)

- 25,700 Pounds (25m

vehicle)

-

Consists 1-car only - -

Acceleration 3 mph/sec - -

Braking 3 mph/sec - -

Grade (sustained) - 6% -

Grade (< 1/4mile) - 7% -

OCS Voltage 750 VDC nominal 925 VDC 500 VDC1AW4 represents the weight of the empty car plus the weight of the full capacity passenger load.

The vehicle will be capable of drawing power from conventional overhead contact wire similar

to those commonly found on light rail or modern streetcar systems. Supplemental means of

propulsion through on-board power storage may be identified, but they are not essential.

Information on dynamic vehicle envelopes will be assumed using conservative values until the

time a specific vehicle is selected. This assumption anticipates the largest envelope that would

be expected from readily available streetcar vehicles present in the U.S. market and any

selection that deviated from this envelope would require less space. The following values will

be used for preliminary engineering design:

Curve radius 200 feet: 6.0 foot minimum offset from centerline

Curve radius > 200 feet: 5.5 foot minimum offset from centerline

The vehicle loading criteria was determined based on a range of values from typical modern

streetcar vehicle specifications. Where applicable, the design shall consider loading conditions

from both a two-truck 20-meter streetcar vehicle (such as the United Streetcar vehicle or the


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Kinkisharyo Ameritram) and three-truck 25-meter streetcar vehicle (Siemens S70 or Kinkisharyo

LRV). These conditions are shown in the figures below.

Figure 2-1

20-Meter Modern Streetcar Loading Condition


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Figure 2-2

25-Meter Modern Streetcar Loading Condition

2.3Alignment GeometryThe track for the Crystal City Streetcar will be positioned either in a shared lane or in dedicated

transit lanes that will be constructed as part of the CCPY Transitway. The streetcar alignment

will be constrained primarily by the existing roadway (or future transitway) geometry. In certain

locations, such as sharp curves, the dynamic and operational characteristics of the vehicle will

limit the alignment geometry.

Where applicable, the conceptual engineering for the Crystal City Streetcar will be based on the

WMATA manual entitled Tram/LRT Guideline Design Criteria (2003). Further guidance for

development of the streetcar alignment will come from Transit Cooperative Research Program

(TCRP) Report 155, Track Design Handbook for Light Rail Transit, Second Edition, and through

application of nationally accepted streetcar design practices. Where roadways and traffic

control devices are affected, the relevant County or VDOT standards will be used.


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The geometry will incorporate desired operational features of the streetcar and its interface

with automobile traffic. These include the following:

Offsetting the streetcar alignment within shared lanes so that automobile drivers can

avoid driving directly on the rails.

Developing the track profile in order to minimize impacts to the existing roadway

pavement.

2.3.1 Alignment Description

This section details the assumptions for the location of the Crystal City Streetcar alignment

within the existing conditions and the Transitway that is anticipated to be in place at the time of

streetcar construction.

The Crystal City Streetcar Project will establish a fixed rail streetcar line from the vicinity of

Potomac Avenue and South Glebe Road to the Pentagon City Metrorail Station in Arlington

County, VA. The project will include both a northbound and a southbound track extending the

approximate 2.5-mile length of the corridor. The northern terminus of the Project is proposed to

be in the vicinity of 12th

Street South and Eads Street in Pentagon City and would coincide with

the eastern terminus of the Columbia Pike Streetcar project. Should the Columbia Pike Streetcar

project be delayed, the Crystal City Streetcar Project will be extended two blocks west to the

vicinity of 12th

Street South and South Hayes Street. The southern terminus would be in the

vicinity of Potomac Avenue and South Glebe Road. The streetcar end of line design will allow for

a future extension south into the City of Alexandria, and it will be designed with consideration

for planned widening of Potomac Avenue and the shared use of the CCPY Transitway with

buses.

2.4Design SpeedsThe streetcar alignment will be developed to allow the streetcar to operate at or below the

posted speed of the roadway on which it operates. By industry standards and the Manual on

Uniform Traffic Control Devices (MUTCD), the design speed shall not exceed 35 miles per hour

(mph) on all routes where the streetcar operates within the existing roadway and is only

controlled by traffic signals (i.e. no crossing gates). Some areas where slower speeds should be

expected are shown below:

90 Degree turns: Where the streetcar turns from one street to another, the speeds will

be limited to approximately 5 mph.

Lane changes: Where the streetcar shifts from one lane to another at an intersection

where it is performing a transit-only maneuver, slower speeds (approximately 15 mph)

should be expected.Streetcar stops: At all streetcar stops, the alignment may have to shift slightly closer to

the curb for level boarding. In addition, the vehicle will stop and briefly dwell

(potentially in mixed traffic).

Turnouts: Most turnouts (switches) for a streetcar system in an urban environment will

be very tight and limited to speeds of around 5 mph.


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3.0The proposed stops for the Project will be designed to accommodate a typical modern

streetcar vehicle which measures from 66 to 82 feet in length. An example of a typical stop

layout is shown below.

(Optional bypass sidewalk shown)

Figure 3-1

Typical Stop Layout

The Crystal City Streetcar Project will incorporate two types of stops: those that are modified

from the CCPY Transitway and those that will be newly constructed for streetcar use. Passenger

amenities that are found with the Transitway stops will also be included with the new streetcar

stops. It is assumed that the modifications required to the Transitway stops will be limited tostructural improvements that will allow streetcar vehicles and buses to use the platforms while

maintaining compliance with the Americans with Disabilities Act (ADA). Typical streetcar stop

design parameters and assumed amenities for each stop are reflected below:

Track Grade through Platform: The track grade will meet the existing roadway or

transitway grades; desirable longitudinal grades should be less than 2%. The platform

grades will be in accordance with ADA guidelines.

Stop Length: Streetcar stops will be approximately 75-90 feet long with a 60-foot long

platform that is long enough to permit boarding from all doors on the vehicle. At some

locations, existing conditions and right of way constraints may preclude the extension of

streetcar stops beyond the length of a single car.

Vehicle-Platform Interface: Bridge plates will be required for the streetcar vehicles in

order to serve the stops that will accommodate both buses and streetcars. In order to

provide ADA-compliant accessibility, accounting for the 14 inch boarding height of the

streetcar vehicle (above top of rail) and the 10 inch height of the stop platform, the

streetcar must be fitted with bridge plates. Stops located on the left side of the vehicle

could be designed with a 14 inch height for level boarding without bridge plates, since

those would be specifically for streetcar use and not shared with buses.

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Track Alignment: Where possible, the track alignment should be tangent horizontally

and vertically through the streetcar stop platform and for approximately 40 feet from

either end of the designated boarding areas. When bridge plates are used, wider gaps

between the vehicle and platform are acceptable because the bridge plate provides

ADA-compliant access to the vehicle. Of the CCPY Transitway stops that are intended to

be reused for the Crystal City Streetcar Project, only the stop at 23rd

Street and Crystal

Drive is on a curve (with radius greater than 21,000 ft); all other Transitway stops are on

tangent.

Width of Stop: The desirable stop platform width should be 12 feet or a minimum of 10

feet. Transitway stops that are along Crystal Drive will be constructed as a shared

platform and through sidewalk.

Platform Height: Typical curb height at the platform edge is approximately 10 inches to

allow boarding of buses and streetcars at the same stop. Ingress and egress from the

streetcar vehicle will therefore include bridge plates for ADA accessibility. In order to

have level boarding for streetcars, provisions to accommodate shared use of stops by

streetcars and buses would need to be made to ensure that there are no conflicts.

Detailed evaluation of platform and vehicle (streetcar and bus) interfaces will be

required in final design to address accessibility.

ADA Access: Grades must be considered at all platform locations. Where the stop is to

be integrated with the sidewalk, no steps may be used along the pedestrian route.

New streetcar stops will have passenger amenities consistent with the CCPY Transitway

stops. These are assumed to include lighting, shelters, benches, and identification

signage, transit information, and trash receptacles, at a minimum. Other amenities, if

any, will be determined as the design is developed further.

4.0Significant project savings can be realized by minimizing unnecessary reconstruction and civil

engineering improvements. It is assumed that a simple cost effective approach will be taken for

the Crystal City Streetcar. The following sections describe some of the common features that

have been used to deliver similar types of street-running transit systems around the country.

These assumptions will serve as the basis of design.

4.1 Cross Slope and Roadway ReconstructionIt is assumed as part of the Project that the limits of reconstruction will be limited to only what

is necessary to install the streetcar track structure and appurtenances. This assumes that no

additional overlay or reconstruction beyond what is absolutely necessary to construct the

streetcar guideway will be included in the project scope or cost. Special conditions may also be

considered, such as limiting reconstruction to the edge of the nearest pavement joint in existing

jointed concrete pavement if it proves to be more cost effective.

Detailed grading is generally not completed until final design. For the purpose of approximating

the amount of pavement reconstruction, the approach mentioned above will be used. The

approach is further outlined in the figure and table below. Cross slope between the rails in

tangent track or reverse superelevation is undesirable and will not be used unless no other

solution exists.


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Figure 4-1

Potential Cross Slope

4.2Lane WidthFor shared auto/streetcar lanes, widths should be 12 feet desirable minimum (in tangent) and

10 feet absolute minimum. This is based on the static envelope of the assumed modern

streetcar vehicle and may need to be modified after the vehicle is selected. The static envelope

of the vehicle mirrors are typically used as the minimum offset for lane striping. All lane widths

are measured from the face of curb to the lane line. In transit-exclusive alignments where thestreetcar is operating by itself or shared only with buses, such as the CCPY Transitway, the

minimum lane width will be based on the dynamic operating characteristics of the design

vehicle.

4.3Track Structure/Pavement ReconstructionAll track for the Crystal City Streetcar will consist of rail embedded in concrete that will allow

buses to operate in shared lanes; ballasted, grass, or direct fixation track will not be used. There

are numerous designs for light rail and streetcar embedded track structures in use throughout

the country. The design of the track slab will ultimately depend upon factors such as the choice

of rail section, local soil conditions, pavement design life expectations, and the potential for

spanning utilities. In a typical installation, the track slab is poured over a compacted basecourse; the base course thickness will vary depending upon the pavement design life and

bearing capacity of the subgrade. The rail will be installed in an elastomeric rail boot that is

continuous to the surface of the pavement on both sides, which is a standard treatment for

stray current protection. Special trackwork will be electrically isolated in a similar manner. The

standard rail gauge of 4 ft, 8 in. will be assumed for this project. Track gauge narrowing in

curves will be examined during future phases of the design, as the streetcar wheel and axle

design are identified.

Table 4.1

Proposed Roadway Design Parameters

Location on Cross Slope Desirable Maximum

A (grade change) 3% 5% (2-3% at cross streets)

B (cross slope) +2% +5%C (cross slope) 2-4% 4.5%

D (cross slope) 0% 1-2%

E (cross slope) - 4-6% -7%

F (curb exposure) 6 inches 10 inches (at stops)


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Most modern light rail and streetcar systems that include shared lanes have been constructed

using embedded girder rail in a concrete track slab. The girder rail has a flangeway integrated

with the rail head, which allows for a consistent flangeway that is suitable for mixed traffic

applications. However, girder rail is only produced in Europe, and it will not satisfy Buy America

requirements for projects that receive federal funding. Alternative rail sections produced in the

United States can be used for embedded track, including traditional tee rail (e.g. 115 RE), which

has been installed in several locations, or a 112 lb block rail section that has only recently

started to be rolled domestically and has been installed in limited quantities in the U.S. and

Europe.

Figures 4-2, 4-3, and 4-4 show typical track slab designs for embedded track using girder, tee,

and block rail sections.

Figure 4-2

Typical Girder Rail Track Structure

Figure 4-3

Typical Embedded Tee Rail Track Structure

(115 RE Rail Shown with Elastomeric Snap-on Flangeway)


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Figure 4-4

Typical Unreinforced Embedded Block Rail Track Structure

4.4Special TrackworkSpecial trackwork refers to the units necessary where tracks converge, diverge or cross oneanother; such units include turnouts, crossings, and crossovers. All special trackwork for the

Crystal City Streetcar will utilize the AREMA based (115RE rail section) design except as modified

to meet the special condition of streetcar system. Special trackwork conforming to European

standards (25 meter or 50 meter turnouts that can be manufactured in the United States) may

be considered if it will best meet the turnouts functional requirements, desired speeds and

local geometric constraints. Special trackwork insulation for stray current protection will utilize

a combination of poured in-place elastomeric grout and/or preformed rail rubber boot. The

location of turnouts and crossovers will be established in coordination with streetcar

operational requirements. Embedded turnout switch machines will be either manual or

powered, depending on location. Turnout switch points will be provided with switch heaters.

4.5DrainageExisting drainage patterns will be maintained throughout the project wherever possible.

Trackwork drainage will require the addition of inlets at the low point of sag vertical curves and

near special trackwork switches. To address potential existing drainage concerns, minimum

longitudinal curb grades will be maintained or introduced within the reconstruction area to the

extent feasible.

Drainage area maps for the Crystal City Streetcar Project area will be developed using a

combination of survey, aerial photography, field observation, and GIS data. The existing

drainage will be evaluated to determine if adjustments to existing inlets or the addition of new

inlets is required. Arlington County and Virginia Department of Transportation methods and

standards will be used for drainage analysis. Because the Crystal City Streetcar will beconstructed in developed areas, it is expected that no additional stormwater management (i.e.,

BMPs) will be required.

4.6ADA Accessibility/UpgradesAlthough impacts to existing facilities are expected to be kept to a minimum, ADA accessibility

must be maintained or introduced if a facility is altered. Pedestrian facilities along the project

corridor will be evaluated during the design process to determine if upgrades are required to

meet ADA guidelines. Necessary upgrades to sidewalks, ramps, and crosswalks at intersections

and other affected locations throughout the project corridor will be included as part of this

project.

4.7Bicycle FacilitiesThe streetcar route is located along several bicycle facilities identified by the Arlington County in

its bikeway plans. The interface between the streetcar tracks and bicycles will be considered at

intersections, along designated bikeways, and other locations where bicycles are likely to use

the roadway. Designs for the areas around new streetcar stops will consider providing bicycle


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racks or lockers. Bicycle facilities included as part of this project will be designed in accordance

with County standards.

5.0General systems requirements typical of a streetcar system similar to the proposed project are

listed below. The systems elements that will be required and discussed are:

Traction Power Supply System (TPSS) Requirements

Overhead Contact System (OCS) Infrastructure

Streetcar Operational Control

5.1Traction Power Supply System RequirementsThe assumptions for the TPSS requirements based on similar types of projects are listed below.

The final size and spacing of the substations for the Crystal City Streetcar will require a detailed

analysis based on the selected vehicle, frequency of service and headways, track alignment

profile, passenger stations, and the speed and load cycle over specific time intervals. This

information will determine the actual transformer/rectifier (system appurtenances thattransform AC supply power to DC) ratings and will confirm utility power demands.

The traction power system assumed is a single trolley wire operating at a nominal system

voltage of 750VDC with rubber-boot insulated rail. The trolley wire size for the positive side of

the traction power system is based on the amperage and ability to meet minimum voltage

requirements for a streetcar vehicle furthest away from any substation and drawing maximum

starting current. The running rails will be used as the traction power systems negative return

from the streetcar vehicle to the substation.

To avoid costly duct banks and with a trolley wire approach, the typical loading requirements

require the use of a minimum 480/240 Vac 600amp (typical peak demand of 300amps) localutility services with 500 kW substations spaced at approximately mile intervals on wired

sections of the alignment. Final determination will be based on the supply analysis study. The

substations can be located in several locations along the alignment including parking structures,

at-grade in adjacent parcels, in the maintenance yard/shop area and even in underground

vaults. Consideration should be made to evenly space the substation sites along and near the

alignment (within 1 or 2 blocks) in order to minimize costly voltage drop duct banks and feeder

lines.

Several types and sizes of substations are available for use. The most cost effective substations

are prefabricated traction power units. If required, these units can be dressed with

architecturally designed external finishes. In addition to space and location, other factors to be

considered include security and accessibility, ease of replacement/installation of equipment,

proximity to utility feeders and to the street feeder pole locations, as determined by the load

study analysis.

The use of underground vaults as an alternative has the obvious advantage of being unobtrusive

and also provides greater flexibility in meeting the spacing requirements. However, these are

usually less convenient with regard to access and equipment maintenance/installation, and have


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Figure 5-2

Substation With Architectural Treatment (Norfolk, Virginia)

5.2OCS InfrastructureThe Overhead Contact System (OCS) will be of an unobtrusive design consisting of a simple

trolley wire supported by poles and cantilever brackets designed to be architecturally

compatible with the streetscape. A single grooved trolley wire will provide power to the vehicle

pantograph. The OCS will be segmented and overlapped to provide individual wire runs

between feeding locations. Electrical sectioning and pole-mounted switching will be provided,as required, at or between feed points. Supporting poleswill be spaced approximately 80-120

along tangent sections, with reduced spacing at connections and curves. Curved sections at the

end loops will require bridle and spider (span) wire support systems. Poles can be of decorative

design, painted, and with attachments for street lighting and possibly traffic signals to reduce

costs and avoid clutter caused by too many poles. For the purpose of this project, it is

assumed that architecturally enhanced painted OCS poles with cantilever supports will be used

in those areas requiring overhead power.

In order to meet the National Electric Safety Code (NESC), the trolley wire must be at least 18

feet under worst conditions above the pavement for shared lanes. Typically, the wire is set at 19

feet to account for wire sag. If there are any cases where the 18 feet minimum clearance cannot

be obtained, the streetcar should be in an exclusive lane or, in some cases, a substandard wire

height could be considered if supported by a detailed evaluation of truck traffic and other tall

vehicles or where special approval is granted by the County and/or VDOT.

5.2.1 Corrosion Control


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In order to prevent premature failures of transit system facilities, utilities, and other

underground structures, measures to address soil corrosion, stray current corrosion, and

atmospheric corrosion will be included in the project design criteria.

5.3Streetcar Operational Control5.3.1 Streetcar Revenue Operations

A Book of Rules for the streetcar system will establish the maximum allowable speed for the

streetcars to be equal to or lower than that currently signed for the roads on which they

operate. It is expected that the streetcar operators will proceed by line of sight and obey

existing street traffic signaling at intersections, as required. Where a special transit-only

maneuver is required, the streetcar movements will be controlled by a two-aspect train signal

and a separate streetcar-only signal phase programmed into the traffic signal controller. A two-

aspect streetcar train signal is typically a light emitting diode (LED) vertical bar indicating that

the vehicle may proceed and a horizontal LED bar indicating that the vehicle must stop. The

streetcar signal head may include an advance signal to inform streetcar operators that the signalis about to change, such as a flashing vertical bar or a flashing horizontal bar. Intersections

requiring a transit-only signal phase will be identified during the conceptual design.

5.3.2 Streetcar Non-Revenue Operations

The streetcar system will allow change-out of streetcar vehicles during daily operational service.

Adequate space will be provided at the end of line stations for storage of additional vehicles,

and the vehicle storage facility will be designed with operational considerations in mind.

5.3.3 Communications

Communications for the streetcar system are intended to be similar to other modern streetcar

systems currently in operation in the United States. Dispatching of the streetcar vehicles will be

accomplished via conventional radio equipment, similar to a transit bus. Automatic Vehicle

Location is intended to be provided as well.

At traction power substation locations, a limited Supervisory Control and Data Acquisition

(SCADA) system will be provided to monitor operations and detect problems within the unit. It

is assumed that communication with the streetcar operation center will be via two-way radio or

phone line.

5.3.4 Fare Collection


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The fare structure for the streetcar system has not been defined for this project, and a means

for collection of fares has not been determined. Provisions must be made to allow for the

following fare collection system methods:

On-board

On platform ticket vendingFare-less operation

Contactless fare collection system

5.3.5 Signal System

Streetcars will operate along the alignment based on line of sight operating rules, requiring

streetcar vehicle operators to obey traffic signals at intersections. At locations where the

streetcar movements may be in conflict, such as at the maintenance facility entrance or where

there is a single track at an end of line, a fully automated signal interlocking may be proposed.

5.4Additional Systems Engineering ConsiderationsThese considerations should be included as the project advances:

Coordination with the Columbia Pike Streetcar project will be required to ensure

compatibility with the traction power system implemented with the Crystal City

Streetcar. Both lines, once constructed, will share a maintenance facility, and vehicles

will need to have the ability to operate on the entire length of both projects

alignments.

If vehicles that can operate without wires are used, the traction power requirements for

such a system will need to be evaluated. Charging locations would be identified based

on the details of the selected system.

6.0In future stages of design, a detailed inventory of the horizontal and vertical position of each

light fixture will be needed to evaluate the position of the fixture relative to the proposed trolley

wire. The main concern is providing safe maintenance access to change the bulb of the light

fixture in proximity to the high voltage overhead trolley wire. There are Occupational Safety and

Health Administration (OSHA) regulated clearance requirements that apply to minimum

clearances and will vary depending upon if the maintenance crew is OSHA qualified or not.

For the purpose of this Project, it is assumed that OSHA qualified crews will be maintaining the

lights, which requires a minimum clearance of three feet, eight inches from the trolley wire to

the luminaires on the pole mast arms. If non-qualified personnel are maintaining the lights, a

minimum clearance of ten feet is required. Further discussion with Arlington County, VDOT, and

Dominion Virginia Power will be required to establish guidelines acceptable to all parties.


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7.0The approach to utility relocation is an extremely important design element to establish

guidelines as early as possible during the project development phase. Utilities are an area in

which every locality has unique guidelines based on the policies of a particular utility owner or

agency.

Existing Utility Composite Drawings will be prepared for the conceptual design submittal using

record drawings, utility maps and Geographic Information Systems (GIS) data obtained from

Arlington County and the utility companies. In areas where more detailed utility information is

critical for the conceptual engineering design or development of cost estimates, subsurface

utility engineering (SUE) will be performed. The final designer for the streetcar should verify and

obtain accurate horizontal and vertical information for all existing utilities using SUE methods as

required.

7.1Conflicts & Relocation AssumptionsThe approach to identifying utility conflicts and relocation requirements is based on permitting

processes and the policies of Arlington County and VDOT. A document detailing the Utility Rulesof Practice will be developed in conjunction with the utility owners and the County. The Rules of

Practice will define the methodology for identifying potential utility conflicts with the streetcar

system and addressing relocations, rehabilitations, other utility adjustments, or procedures for

maintaining utilities in place.

It is recommended that all utilities crossing under the proposed streetcar be encased. The

exception is storm drain, which is self-encasing. Encasing utilities will allow utility companies to

access their facilities without disrupting streetcar operations.

7.2Areas of ImportanceIn Arlington County, Crystal Drive south of 27 th Street (near the Hyatt hotel) is located above anunderground parking garage, and multiple utilities are believed to be in the right of way at

shallow depths. Other parking garages extend under Crystal Drive as well, and the locations of

utilities in those areas are not well defined.

Portions of South Bell Street bear directly on underground passageways and parking structures.

In addition, the proposed streetcar alignment crosses over existing WMATA Metrorail tunnels at

18th Street and Bell Street, and 18th Street and Crystal Drive.

It is suggested that discussions with utility owners occur based on the preliminary data to start

the coordination process and establish which utilities will be relocating.

8.0The implementation of streetcar service within existing streets in Arlington County will require

evaluation and likely adjustments to traffic operations and traffic signals. Many factors will need

to be considered during the design. A brief discussion of typical traffic-related design issues that

should be considered for this type of project are described in the following sections.


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8.1Traffic OperationsTraffic operations are an integral part of any streetcar service. As the project moves forward

into design, it will be vital that a detailed traffic analysis be performed, which will identify areas

of specific operational constraints, areas of impact on adjacent traffic, streetcar running times,

and other parameters that can be addressed through design.

In most cases, typical streetcar operation is similar to that of other vehicles in shared lanes by

line of sight, with no additional traffic signal heads required unless a transit only phase is used

and incorporated into the signal operation. This would typically occur if the streetcar is

operating in a transit-exclusive lane, or if a separate phase is needed for the streetcar to

transition from an exclusive lane into a shared lane.

8.1.1 Transit Priority

It is assumed that Transit Signal Priority (TSP) will be used for the Crystal City Streetcar. TSP

helps ensure streetcar travel time reliability by adjusting traffic signal phasing to give a green

signal for streetcars that are approaching, minimizing the amount of time that they are stoppedat intersections. The effectiveness of TSP will be verified with the VISSIM model, and

operational details will be developed in future phases of the design.

8.2Traffic SignalsThere are many signalized intersections within the proposed Crystal City Streetcar alignment.

Traffic signals are expected to be installed or modified as part of the CCPY Transitway project,

and other signals along the alignment may be impacted. Typically, any signal equipment located

over the streetcar lane will need to be removed in order to provide adequate clearance to the

overhead trolley wire.

8.2.1 Traffic Signal Equipment

Controller: The controllers along the proposed streetcar path will be inventoried and

evaluated to determine if they are capable of accommodating advanced streetcar

operations. The requisite modifications required, if any, for advanced streetcar

operation will be noted in the inventory process.

Traffic Signal Pole and Foundation: It is common for the trolley wire (single wire) to be

supported by span wire connected to OCS poles or joint-use traffic signal poles. It is

often desirable to minimize the number of poles within the right-of-way. One way to

accomplish this is to have joint use poles on which traffic signals and OCS wires are

supported, as shown in Figure 8-1.Detection: Equipment must be provided to detect the streetcar at intersections. This

equipment may be similar to what is used for detecting other vehicles, such as video

detection. If the streetcar needs to be identified separately from other vehicles,

Opticom sensors or train-to-wayside communication (TWC) devices can be used.


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Figure 8-1

Joint Use Traffic Signal and OCS Pole

8.3Pavement Markings & SignagePavement markings will conform to Manual on Uniform Traffic Control Devices (MUTCD)

requirements and the standards of the relevant jurisdiction (Arlington County or VDOT).

9.0Assumptions for structures that may be affected by the streetcar will be described in a separate

report.

10.010.1Survey ControlThe basis of survey control for this project is the Virginia State Plane, North Zone (1983).

Existing Arlington County control stations will be used to establish survey control. Should any

supplemental survey be required, additional control points will be created.

10.2Base MappingFor the conceptual design, base mapping will consist of georeferenced aerial photography and

existing topographic survey data provided by Arlington County. As critical areas are identifiedduring the design, supplemental survey may be taken of these specific locations if necessary.

10.3Utility Field MappingExisting utility information within the project corridor will be obtained from utility companies,

Arlington County, and from development projects in the vicinity. This information will be

compiled into a single utility base map for use in evaluating alternatives and developing cost

estimates for the conceptual design. Additional subsurface utility location information may be


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obtained in critical areas along the corridor to supplement the mapping created from data

records.

10.4Geotechnical Boring LocationsGeotechnical borings are anticipated during preliminary engineering. For the conceptual design,

visual investigation and a review of readily available geotechnical reports will be used to identifypotential issues and evaluate the geotechnical conditions in the project corridor.

11.0The maintenance and storage facility requirements for the Crystal City Streetcar Project will be

coordinated with the Columbia Pike Streetcar Project. Potential sites and functional

requirements for the maintenance and storage facility (or facilities) will be identified and

documented in a separate report.

Documents

Crystal City Basis of Design