School Crossing Sign: S1-1 Assembly, Sizes and Color Rules
Updated · By the Cone to Curb editors
A school crossing sign is the MUTCD's School Crossing assembly: the School (S1-1) sign, two children walking on a diamond, with a downward-pointing arrow (W16-7P) plaque below it, set at the crosswalk itself. On a conventional road the S1-1 is 36 x 36 inches, and every school warning sign must have a fluorescent yellow-green background.
| Sign or plaque | Code | Conventional road | Minimum | Oversized |
|---|---|---|---|---|
| School | S1-1 | 36 x 36 | 30 x 30 | 48 x 48 |
| Downward diagonal arrow | W16-7P | 21 x 15 | (none) | 30 x 21 |
| AHEAD | W16-9P | 24 x 12 | (none) | 30 x 18 |
| XX FEET (2 lines) | W16-2P | 24 x 18 | (none) | 30 x 24 |
| XX FT (1 line) | W16-2aP | 24 x 12 | (none) | 30 x 18 |
Sizes in inches, from MUTCD Table 7B-1. The oversized column is required on expressways in school areas and recommended on roads with four or more lanes and posted speeds of 40 mph or more.
Two assemblies, two jobs
| Assembly | Made of | Goes |
|---|---|---|
| School Advance Crossing | S1-1 + AHEAD or XX FEET plaque | Ahead of the first school crossing in each direction (Table 2C-3 gives the distance) |
| School Crossing | S1-1 + W16-7P down arrow plaque | At the crosswalk, or as close to it as possible |
The advance assembly can be left out where a School Zone sign already marks the start of the zone ahead of the crossing. If the crosswalk is on a side street just around a corner, the advance assembly can carry an arrow plaque on each approach so turning drivers know a crossing is coming.
Color: fluorescent yellow-green, not yellow
Section 7B.01 makes fluorescent yellow-green mandatory for school warning signs and their plaques. Plain yellow S1-1 signs and yellow arrow plaques are out, and you shouldn't mix the two colors in one zone. Fluorescent yellow-green comes in prismatic sheeting grades; ask for the sheeting type on the quote. School area signs must also be retroreflective or lit.
Where it can't go
- Only at school crossings: crossings next to schools or on an established school walking route. Not at every crosswalk near a school.
- Not on an approach with a STOP or YIELD sign, except on a yield-controlled entry to a roundabout or a yield-controlled right-turn lane, where the crosswalk is at least 20 feet before the yield point.
Other tools for the crossing itself include an in-street pedestrian or school crossing sign (12 x 36 inches) and, ahead of it, a 12-inch in-street S1-1 sign on the special flexible mount.
Mounting
Post-mounted school signs follow the usual heights: at least 5 feet to the bottom of the sign in rural areas and 7 feet where people park or walk (Section 2A.15). A plaque mounted below may sit 1 foot lower.
Ordering checklist
- Count crossings and approaches: one School Crossing assembly per approach to each crossing, plus the advance assembly where needed.
- Pick the size column from the road, not the budget.
- Specify fluorescent yellow-green prismatic sheeting for the sign and every plaque.
- Order posts and hardware for the full assembly: sign on top, plaque below.
Mistakes we see
- A yellow arrow plaque under a yellow-green sign. The plaque must match.
- Using the assembly at a stop sign. Not allowed except the roundabout and right-turn cases.
- 30-inch signs on a four-lane 45 mph road. That road wants the oversized 48-inch sign.
What it costs
Ballpark U.S. prices in late 2026: $90 to $200 for a 36-inch S1-1 on 0.080-inch aluminum with fluorescent yellow-green prismatic sheeting, $30 to $70 per plaque, and $30 to $80 per post with hardware.
Where to buy
Sign shops and traffic safety distributors that make MUTCD signs to order, and many state prison industries programs that sell to agencies. Ask for the sheeting type, aluminum thickness and that the plaque color matches.