Section 3: Approving a Quiet ZoneAnchor: #i1001068
Qualifying for a Quiet Zone
A Quiet Zone may be established without approval of the FRA if:
- one or more Supplementary Safety Measures (SSMs) is installed at all public at-grade crossings within the Quiet Zone
- the Quiet Zone Risk Index (QZRI) is at or below the Nationwide Significant Risk Threshold (NSRT) after any necessary SSMs are installed
- the QZRI is at or below Risk Index with Horns after any necessary SSMs are installed.
The NSRT is an average value established for all gated public crossings in the U.S. where train horns are sounded. It is updated annually by the FRA and published on the FRA website. Any Quiet Zones which qualify under this rule no longer qualify if a revised NSRT drops below the QZRI.
Local governments may also establish a Quiet Zone with approval of Alternative Safety Measures to be approved by application to the FRA.Anchor: #i1001103
Supplementary Safety Measures (SSMs)
Approved Supplementary Safety Measures (SSMs), to be installed on all approaches to an at-grade crossing, with associated effectiveness, include:
- temporary closure of at-grade crossing during hours which Partial Quiet Zone is in effect (Effectiveness: 1.0)
- four-quadrant gate systems with no presence detection (Effectiveness: 0.82)
- four-quadrant gate systems with presence detection (Effectiveness: 0.77)
- four-quadrant gate systems with traffic of at least 60 feet with or without presence detection (Effectiveness: 0.92)
- gates with channelization devices (Effectiveness: 0.75)
- gates with non-transversable curbs with or without channelization devices (Effectiveness: 0.80)
- one-way street with gates (Effectiveness: 0.82)
- permanent closure of at-grade crossing (Effectiveness: 1.0).
The effectiveness represents the ability of the SSM to reduce grade crossing crashes. For example, closing a crossing reduces 100% of at-grade crossing crashes while installing gates with channelization devices reduces 75% of crashes. Effectiveness values are subject to change by the FRA.
The following requirements apply when installing SSMs:
- All approach and exit lanes must be covered by gates in a four-quadrant system.
- Horizontal distance between two gate ends must not be more than two (2) feet.
- Horizontal distance between a gate and a raised median or channelization device or curb must not be more than one (1) foot.
- Medians or channelization devices must extend at least 100 feet from gate arm, or if there is an intersection within 100 feet of the gate, the median or channelization device must extend at least 60 feet from the gate arm.
- Non-transversable curbs must be a minimum of 6 inches in height and only used when the roadway speed limit is 40 mph or less.
- Any streets, alleys, or commercial driveways within 60 feet of at-grade crossing (parallel with rail) must be closed if medians or channelization devices are proposed.
- Non-transversable curb must extend back 100 feet from the gate if only one gate is used on a one-way street.
Alternative Safety Measures (ASMs)
Alternative Safety Measures (ASMs) may also be proposed to the FRA who will determine the effectiveness used in Quiet Zone Risk Index calculations. There are three types of ASMs:
- Modified SSMs (i.e. channelization devices that are less than 60 feet long)
- Non-Engineering ASMs (i.e. traffic law enforcement program)
- Engineering SSMs (i.e. engineering improvements to address sight distance).
Quiet Zone Risk Index (QZRI)
A Quiet Zone Risk Index (QZRI) must be calculated whenever SSMs are not installed at all crossings. To calculate a QZRI, the following procedure is followed:
- Determine the crossing Risk Index with Horns (RIWH) for each public at-grade crossing in the Quiet Zone prior to any adjustments for SSM effectiveness.
- Determine the crossing Risk Index (Crossing Risk Index = RIWH x 1.668 x [1-Effectiveness]) for each public at-grade crossing in the Quiet Zone after any current or planned SSMs/ASMs are installed.
- Determine the RIWH (average of crossing RIWH in absence of any existing or proposed SSMs for all public at-grade crossings in the Quiet Zone).
- Determine the QZRI (average of Crossing Risk Index for all public at-grade crossings in the Quiet Zone).
The initial RIWH calculation may be determined from the FRA website Quiet Zone Calculator and is a calculation based on:
- the trains per day
- the number of day through trains
- the total switching trains per day
- the number of main tracks
- the number of other tracks
- if the crossing is in an urban or rural location
- if the roadway is paved or not
- the maximum train speed
- the number of roadway lanes
- the number of years of crash data
- the number of crashes in crash data years.
NOTE: Any existing grade separated or closed crossings may not be considered when calculating the QZRI. For any proposed closed crossings, the existing traffic counts at the crossing must be distributed among adjacent crossings for AADT calculations.
Visit the FRA website Quite Zone Calculator for more information.Anchor: #i1001328
Wayside horns may be used in place of locomotive horns at individual or multiple at-grade crossings within Quiet Zones and are considered a one-for-one substitution for train horns. The wayside horn is a stationary horn located at a rail-highway at-grade crossing which directs noise down the roadway rather than at surroundings. Any at-grade crossing with a wayside horn is not considered when calculating the QZRI.Anchor: #i1001338
TRF-RSS is mailed a copy of an NOI by the local government. TRF-RSS forwards the NOI to the District Railroad Coordinator for any comments and compiles these comments with any comments from TRF-RSS for response to the local government.
NOIs are reviewed to ensure the proposed Quiet Zone:
- meets requirements described in this chapter
- meets requirements typically included on Federal Signal Program (FSP) projects
- is calculated correctly if the Quiet Zone applies because the QZRI is less than or equal to the RIWH or NSRT
- individual crossing data (traffic counts, train counts, etc.) is correct if the Quiet Zone applies because the QZRI is less than or equal to the RIWH or NSRT
- includes all crossings along the section of rail indicated as shown in TRIMS.
For more information on reviewing plan sets, see Chapter 7.
Any data discrepancies noted between the NOI and TRIMS are verified between TRF-RSS, the local government, and the railroad company. TRF-RSS coordinates any inventory updates in TRIMS and with the FRA.Anchor: #i1001388
Application to the FRA
If any ASMs are included on the NOI, the local government will have to submit an application to the FRA for approval of the proposed Quiet Zone.
The following parties are provided a copy of the application to the FRA by the local government:
- railroad companies operating on crossings within the Quiet Zone
- TxDOT (acting as state agency responsible for grade crossing and road safety)
- any private landowners with private crossings within the Quiet Zone
- any other government agencies with jurisdiction over public crossings within the Quiet Zone.
The application must include:
- inventory forms for all crossings prior to any Quiet Zone upgrades. Any changes to reported inventory information must be transmitted to TRF-RSS.
- explanation of safety improvements the local government will implement in order to qualify for the proposed Quiet Zone
- a copy of the recommendations of the diagnostic team and a list of anyone who attended the diagnostic inspection
- a copy of comments from TxDOT and all operating railroad companies in response to the NOI and any response to the comments
- commitment to implement proposed safety improvements
- data analysis that shows proposed improvements will reduce QZRI below NSRT or RIWH
- five-year projected vehicular and rail traffic counts for any new crossings located within proposed Quiet Zone.