MUTCD I1-1: Traffic Signal Speed Sign

The I1-1 sign is covered in Section 2H.04 of the Manual on Uniform Traffic Control Devices, 11th Edition. Below are the provisions from that section that describe when the sign is used and how it is placed.

What it means and when it is used

• Option · Permitted (may)
  The Traffic Signal Speed (I1-1) sign (see Figure 2H-1) displaying the legend SIGNALS SET FOR XX MPH may be used to indicate a section of street or highway on which the traffic control signals are coordinated into a progressive system timed for a specified speed at all hours during which they are operated in a coordinated mode.
• Option · Permitted (may)
  If different system progression speeds are set for different times of the day, a changeable message element may be used for the numerals of the Traffic Signal Speed sign. If the system is operated in coordinated mode only during certain times, a blank-out version of the Traffic Signal Speed sign may be used to display the entire message only during those times.

Placement and mounting

• Standard · Required (shall)
  Library I4-1 2H.01 24 x 24 — Recycling Center I4-2 2H.01 30 x 36 — Acknowledgment I20-1 2H.13 36 x 30 * 72 x 48 * Acknowledgment I20-2 2H.13 36 x 30 * 72 x 48 * Acknowledgment I20-3 2H.13 42 x 24 * 96 x 36 * Acknowledgment - Rest Area I20-4 2H.13 56 x 36 * 72 x 48 * Acknowledgment - Welcome Center I20-4a 2H.13 56 x 36 * 72 x 48 * Acknowledgment (plaque) I20-5P 2H.13 Varies x Varies*** Varies x Varies*** Last In…
• Standard · Required (shall)
  If used, the Traffic Signal Speed sign should be mounted as near as practical to each intersection where the timed speed changes, and at intervals of several blocks throughout any section where the timed speed remains constant.

Where to read the rest

• Full text: MUTCD Section 2H.04: Traffic Signal Speed Sign
• Mounting height, lateral offset and retroreflectivity for any sign: MUTCD sign placement guide