BNSF Grade Separation Guidelines: Clearances, Drainage, and Costs

BNSF’s grade separation guidelines set a minimum permanent vertical clearance of 23 feet 6 inches from the top of the highest rail to the lowest point of an overhead structure, and every design, review, and construction decision on the project has to protect the railroad’s current operations and future capacity.¹ The sponsor pays for the design, the construction, future replacement, long-term maintenance, and any BNSF crew time the work requires. The rules below come from the BNSF/UPRR Joint Guidelines and the associated policy documents; getting the details right before the first submission is what keeps a project on schedule.

Starting the Project With BNSF

The sponsor opens the file with a formal letter of intent and a preliminary concept plan showing property boundaries, the proposed structure alignment, and vertical profiles. BNSF uses that package to judge how the work would affect current rail operations and any planned future track.

The initial submission also needs a detailed traffic study, an analysis of utility conflicts inside the right-of-way, and, if drainage patterns will change, a comprehensive drainage report. Environmental clearances and confirmation of federal and state compliance have to be in hand before BNSF will begin its formal engineering review.¹

Design Review Stages and Timelines

The BNSF Local Representative forwards the concept package to Central Engineering, and the review then follows a defined sequence that depends on structure type.

Overhead structures (road over rail) go through four stages: Concept, 30% design, Final Plans, and Construction Phase Design. Each stage carries an estimated four-week review, assuming the submission is complete.¹

Underpass structures (rail over road) go through five stages: Concept, 30%, 60%, Final Plans, and Construction Phase Design. Most stages take four weeks, but the 60% review takes six because of the deeper look at structural calculations, geotechnical reports, and construction phasing. Incomplete submittals stretch these timelines further.¹

Written approval of final plans expires two years from BNSF’s signature. If construction has not started inside that window, the railroad can require a fresh design review at the sponsor’s expense before it issues the Right-of-Entry Agreement.¹

Permanent Clearances

The 23-foot-6-inch minimum vertical clearance for overhead structures is measured from the top of the highest rail to the lowest obstruction. That is two inches more than UPRR’s 23-foot-4-inch standard, which matters on joint-line corridors where both railroads’ requirements apply.¹

The vertical clearance envelope must extend at least 9 feet to the field side of the outermost existing or future track, perpendicular to that track’s centerline. On curved track, the 9-foot distance grows by either 6 inches total or 1.5 inches per degree of curve, whichever is greater.¹

For underpass structures, the roadway clearance beneath the rail bridge depends on the superstructure type:

Steel with five or more beams, or four or more deck plate girders per track: 16 feet 6 inches
Concrete, or steel through plate girders with bolted bottom flanges: 17 feet 6 inches
Steel through plate girders without bolted bottom flanges: 20 feet

These clearances apply over the entire roadway width for new or reconstructed structures.¹

Horizontally, all abutments and piers must sit more than 27 feet from the centerline of the nearest existing or future track, measured perpendicular. UPRR’s threshold is 25 feet. BNSF prefers piers and abutments entirely outside the right-of-way; anything placed inside the right-of-way or within 25 feet of a track centerline needs crash walls or other protective measures. A pier footing within 25 feet of the nearest track must be buried at least 6 feet below the base of rail.¹

Future track centerlines factor into clearance math too. Future freight tracks must be at least 20 feet from the nearest existing track centerline, and future commuter tracks must be at least 25 feet from the nearest existing or future freight track. On curved track, horizontal clearances increase by 6 inches total or 1.5 inches per degree of curve, whichever is greater.¹

Structural Design Requirements

When a bridge maintenance access road is part of the main railway structure, the design must accommodate Cooper E-80 live load for future track modifications. On underpass structures, steel superstructures with composite concrete decks are designed as composite for E-80 live load and impact; steel superstructures with composite steel decks are designed as non-composite for E-80 live load and impact.¹

BNSF accepts only simple spans with ballast decks on underpass structures. Cast-in-place concrete superstructures are not accepted. Multi-track structures with spacing under 20 feet must still be designed for a minimum 20-foot center-to-center spacing. The outside edge of a bridge maintenance access road must be at least 27 feet from the centerline of the nearest existing or future track.¹

Drainage Rules That Trigger Rejections

Storm water runoff must be diverted entirely away from the railroad right-of-way at all times. That single rule sits behind most of the drainage detail in the guidelines, and it is one of the fastest ways to lose a plan review.

On overhead structures, deck scuppers cannot discharge onto track or access road areas. Downspouts must connect to the storm drain system or empty into drainage ditches with concrete splash blocks or aggregate lining at the discharge point, and they should sit on the side of the pier opposite the tracks.¹

On underpass structures, the superstructure needs a minimum longitudinal grade of 0.2%. Designers can slope drainage toward one end or, on longer structures, grade toward both ends. During construction, existing track ditches stay open at all times. After construction, erosion and sediment control devices come out, sediment deposits are cleared, and the site is restored to pre-construction condition. Where abutments or piers interfere with drainage ditches, the designer must provide an alternative drainage method backed by a hydraulic study.¹

Utility Attachments and Relocations

BNSF discourages any utility attachment to an overhead structure. Pipelines carrying liquids may not be attached to or hung from an overhead structure at all. If a non-liquid utility is authorized for attachment, it needs a separate license agreement.²

Any utility installation, relocation, or removal on BNSF property requires a Utility License Agreement, with plans submitted and approved before work starts. A relocated utility is treated as a new installation and must meet current policy in full even if the line already existed in the corridor. The utility owner pays for removal, relocation, and maintenance regardless of who required the work, and pays for the BNSF construction inspector who must be on site for excavation, grading, or construction on railroad property. Railroad flagging is required whenever a contractor operates equipment near, over, or under BNSF property in a way that could endanger operations.³

Temporary Clearances During Construction

Shoring, falsework, and equipment operating over the tracks have to meet tighter minimums than many sponsors expect. Temporary vertical construction clearance is 21 feet 6 inches above the top of the high rail for all tracks, and formwork deflection cannot reduce that anywhere.¹

Temporary horizontal construction clearance is 15 feet from the centerline of the nearest track to any physical obstruction, including formwork, stockpiled materials, parked equipment, and bracing. On curved track, that distance grows by 6 inches total or 1.5 inches per degree of curve, whichever is greater. Support systems have to be designed so that train movements are never interrupted.¹

Construction Notice, Flagging, and Final Acceptance

The contractor must notify BNSF’s Manager of Public Projects at least 30 calendar days before work begins, and a pre-work meeting with the Manager of Track Maintenance is required to coordinate activities and confirm temporary clearance arrangements.⁴

Any work within 25 feet of an active track centerline requires a BNSF-provided flagger at the contractor’s expense. That includes crane operations, excavation that could undermine a track, and overhead wire work that could fall on the track. Flagging is a safety rule, not a discretionary service, and visual detection alone does not satisfy it.⁵

Final observation and acceptance of the completed structure by BNSF engineering personnel is required before the contractor demobilizes.

Agreements Required Before Construction

Two agreements have to be executed before any work happens on BNSF right-of-way. The Construction and Maintenance Agreement governs the design, construction, and long-term upkeep of the structure. The Right-of-Entry Agreement authorizes physical access and sets safety and insurance obligations.¹

The C&M Agreement also defines who maintains what after completion. The public entity typically takes the bridge deck, roadway, drainage systems, and approaches. BNSF keeps the track structure and any railroad-specific facilities installed as part of the project.⁶

Who Pays, and On What Schedule

The sponsor covers design, construction, future replacement, and long-term maintenance. When BNSF’s own crews perform force-account work, the railroad issues progressive invoices, and the sponsoring agency reimburses each one within 30 days. The final post-completion invoice carries a 90-day payment window.⁶

Federal Funding Sponsors Commonly Use

The Section 130 Railway-Highway Crossings Program, funded through the Highway Safety Improvement Program, pays for eliminating hazards at public railroad crossings. Section 130 projects receive a 100% federal cost share with no local match required.⁷ The Infrastructure Investment and Jobs Act authorized $245 million annually for the program from fiscal year 2022 through 2026.⁸

Class I railroads including BNSF are not eligible to apply directly for Reconnecting Communities Pilot grants or Corridor Identification and Development funding, but they can partner with eligible applicants. On Reconnecting Communities capital construction grants, the local cost share ranges from 20% to 50%, with other federal funds available to bring the total federal share up to 80%.⁹

Any federally funded grade separation must comply with Build America, Buy America. All iron, steel, manufactured products, and construction materials incorporated into the project must be produced in the United States, and the domestic content threshold for manufactured products is 55% of the total cost of all components.¹⁰ Public interest, nonavailability, and unreasonable cost waivers exist, along with a de minimis waiver when non-compliant products total the lesser of $1,000,000 or 5% of applicable project costs.¹¹

1
BNSF. BNSF Guidelines for Railroad Grade Separation Projects
2
BNSF Railway. BNSF Construction Engineering Instructions
3
BNSF Railway. Utility Accommodation Policy
4
BNSF Railway. Exhibit C – Contractor Requirements
5
BNSF Railway. BNSF Guidelines for Industry Track Projects
6
BNSF Railway. Grade Crossing Construction and Maintenance Agreement
7
Office of the Law Revision Counsel. 23 USC 130 Railway-Highway Crossings
8
Federal Highway Administration. Railway Highway Crossing Program Overview
9
BNSF Railway. Reconnecting Communities Pilot Program
10
eCFR. 2 CFR Part 184 – Buy America Preferences for Infrastructure Projects
11
Federal Railroad Administration (FRA). Buy America