Train horns are one of the most common reasons people look up the crossings near their home. Locomotive horns are routinely sounded as trains approach public crossings, and the federal route for a community that wants them to stop is a quiet zone under 49 CFR Part 222. This note sets out what the rules require of a quiet zone, which notices a city must send and when, and how the crossing inventory sits at the center of the process.
What a quiet zone is
The definitions are in 49 CFR 222.9. A quiet zone is a segment of a rail line with one or more consecutive public highway-rail crossings at which locomotive horns are not routinely sounded. Two details in that sentence matter. The zone is defined along the railroad, as a stretch of line, not as a neighborhood on a map. And it is built out of public crossings; private and pedestrian crossings inside the stretch are dealt with, but they do not define it.
The rules use "locomotive horn" for the device itself, and note that the railroad industry treats "train whistle", "locomotive whistle" and "train horn" as the same thing. They also define a wayside horn: a stationary horn at the crossing that sounds toward approaching drivers when a train comes, instead of the horn on the train. With a wayside horn the sound is aimed at the road rather than carried along the line by the train.
Rail Crossing Atlas explains in its short guide why trains honk at night when horns sound and whether they can still sound inside a zone. This note looks at how a zone comes to exist.
Full-day, partial, new and older zones
A quiet zone can cover the whole day or only part of it. The rules define a partial quiet zone as one where horns are not routinely sounded for a specified period during the evening or night. For a new partial zone the hours are fixed: 10 p.m. to 7 a.m., with horns sounded as usual for the rest of the day.
The rules also separate new zones from older ones. Some communities had restricted horns, by state law, local ordinance or agreement with the railroad, before the federal rule existed. The rule keeps such places as pre-rule quiet zones, with three dates that come up again and again:
- the length of a pre-rule zone may stay as it was on 9 October 1996;
- its crossing equipment must stay at least at the level that existed on 18 December 2003, and may be upgraded but not reduced;
- its advance warning signs had to be in place by 24 June 2008.
Adding a public crossing to a pre-rule zone, other than by joining two neighboring pre-rule zones, ends its older status: the zone then has to meet every requirement for a new one. Most of what follows describes new zones, the case a city faces today.
Who leads
The work is led by a public authority, which the rules define as the public body responsible for traffic control or law enforcement at the crossing. A zone may include crossings in more than one jurisdiction. The railroad does not create the zone. It receives the notices, takes part in reviews and comments, and its engineers stop routine horn use once the zone is established.
Quiet zones can also rely on extra measures beyond the minimum equipment. The rules call them supplementary measures, which are systems or procedures provided by the traffic control or law enforcement authority that FRA has found to be an effective substitute for the horn, and alternative measures, which FRA accepts after reviewing a particular case. The rules also define an index for the corridor that accounts for the loss of horns and gives credit for such measures. The Rail Crossing Atlas guide how to get a railroad quiet zone covers the practical side: the crossing review, estimates and timing.
The minimum requirements
Section 222.35 sets the floor every new zone must meet.
- LengthAt least one-half mile along the railroad. The minimum is waived for a new zone added onto an existing one, provided there is no public crossing where horns are routinely sounded within one-half mile of it. New zones on the same line within one jurisdiction must be separated by at least one public crossing, unless one is being added onto the other.
- Flashing lights and gatesEvery public highway-rail crossing in a new zone must have both, in place by the date the zone starts, meeting the federal traffic control device standards. They must have constant warning time equipment where reasonably practical, and power-out indicators.
- Advance signsEach road approach to every public and private crossing in the zone needs a sign telling drivers that train horns are not sounded at the crossing, or not sounded at night in a partial zone. Crossings with wayside horns that meet the rule are exempt.
- BellsAt public crossings with pedestrian traffic that already have automatic bells, the bells must be kept in working order.
- Private and pedestrian crossingsEach must be dealt with under the provisions written for it elsewhere in Part 222.
The equipment rule ties straight back to the record: a public crossing listed with signs only, or with lights but no gates, would need both gates and flashing lights before it could be part of a new quiet zone.
Two notices and their timing
The paperwork is set out in section 222.43, last amended in 2025. For a new zone there are two written notices.
The Notice of Intent goes to every railroad operating over the public crossings in the zone, the state agency in charge of grade crossings, the state highway agency and others the rule names. It must list each public, private and pedestrian crossing in the zone by its U.S. DOT inventory number and street name, state whether horns would stop for 24 hours or from 10 p.m. to 7 a.m., briefly explain the authority's tentative plans, and name a contact person. Recipients then have 60 days to comment. The period can end sooner once the authority has written comments, or written statements of no comment, from each railroad and both state agencies.
The Notice of Quiet Zone Establishment cannot be mailed less than 60 days after the Notice of Intent unless those comments or statements are in hand. It must give the date the zone takes effect, at least 21 days after mailing. Among its contents:
- the list of crossings by inventory number and street name;
- the provision of Part 222 the zone is established under;
- the hours, 24 hours or 10 p.m. to 7 a.m.;
- the person responsible for monitoring compliance and the list of recipients;
- a statement signed by the chief executive officer of each participating authority, certifying that the information is accurate and complete.
Where the inventory comes in
Both notices identify crossings by their inventory numbers, so the first practical step for a city is to pull the record for every crossing along the stretch. The establishment notice then goes further: it must include an accurate and complete inventory form for each public, private and pedestrian crossing in the zone showing conditions before any new measures, and an accurate, complete and current form showing the measures in place when the zone is established. Measures that the form cannot fully describe are described separately.
That makes the record both the starting point and the proof. A record that is out of date, with an old device count or a missing crossing, has to be put right before the notice can be accurate. The note on warning devices in the inventory explains the device boxes the forms rely on, and the note on reading a crossing record shows where the quiet zone field sits on the form.
Quiet zones in the inventory today
In the FRA inventory of 3 November 2026, Rail Crossing Atlas counts 4,921 public crossings whose records carry a quiet-zone designation, in 44 states. The designation takes one of three values, so the groups do not overlap:
- full-day quiet zones: 4,379 crossings;
- partial quiet zones: 175 crossings;
- the Chicago-area horn exemption: 367 crossings, a separate designation rather than a zone set up under the steps above.
The three add up to the total. The quiet zone field on each record is provided by FRA, so it reflects FRA's records rather than local plans. State-by-state figures are on the Rail Crossing Atlas quiet zones page. If your street is near a crossing that is not in a zone, the steps above are the route the rules set out, and they start with the record.
Sources
Figures are as the source showed them on the date given. Rail Crossing Atlas figures come from the FRA crossing inventory of the date stated in the text.
- 49 CFR 222.9: definitions for locomotive horn use at crossings (Cornell Legal Information Institute). Read 3 November 2026.
- 49 CFR 222.35: minimum requirements for quiet zones (Cornell Legal Information Institute). Read 3 November 2026.
- 49 CFR 222.43: notices and information required to create a quiet zone (Cornell Legal Information Institute). Read 3 November 2026.
- Rail Crossing Atlas: quiet zones by state. Read 3 November 2026.
- Rail Crossing Atlas guide: how to get a railroad quiet zone. Read 3 November 2026.
- Rail Crossing Atlas guide: why trains honk at night. Read 3 November 2026.