A Lane and Sidewalk Closure on a 35-mph Arterial
You arrive at 8:15 a.m. on a weekday at a utility repair on a 4-lane urban arterial with a two-way left-turn lane; the posted speed is 35 mph. The right lane is closed for 300 feet. The contractor set the merging taper with cones spaced 15 feet apart over 150 feet, placed the first advance warning sign 200 feet ahead of the taper, and left a 60-foot space between the last cone and the work vehicle, which is parked inside that space along with the crew's pickup. No shadow vehicle is used. The sidewalk on that side is closed with tape, and pedestrians, including a wheelchair user, are being directed into the adjacent travel lane. Work runs through Friday.
1. Evaluate the taper length, the advance warning distance, and the buffer space. Give the values the setup should have.
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Merging taper. For speeds of 40 mph and below, the merging taper length is L = W x S, where W is the lateral offset in feet and S the posted speed in mph. Here: 12 feet x 35 mph = 420 feet. The 150-foot taper is less than half the required length, so drivers get no distance to see and merge. Device spacing along a proper taper can be widened to suit the speed (tables commonly allow up to about 40 feet at 35 mph); the 15-foot spacing is not the problem - the length is.
Advance warning. For an urban arterial at 35 mph, the first sign should be on the order of 350 feet ahead of the taper per the advance warning sign spacing table in the agency's adopted MUTCD edition, not 200 feet. Verify against the edition in the contract.
Buffer space. The space between the end of the taper and the work area absorbs errant vehicles and must be free of workers, equipment, and stockpiles. Buffer space is set from stopping sight distance - at 35 mph, about 250 feet. The crew's pickup and work vehicle parked in a 60-foot space is a direct intrusion hazard, and with no shadow vehicle there is nothing protecting the crew.
Direction: correct all three before work continues, and issue a written TTC deficiency notice.
2. Pedestrians, including a wheelchair user, are being routed into the travel lane. What is required, and what do you do first?
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A sidewalk cannot be closed without an accessible alternate route. A temporary pedestrian access route must provide:
- At least 4 feet clear width, with passing spaces where the route is long or constrained.
- A firm, stable, slip-resistant surface.
- Cross slope of 5 percent maximum and running slope consistent with accessible design.
- Detectable warnings and proper ramps at street crossings, plus advance pedestrian detour signing.
Routing a wheelchair user into a live travel lane fails every one of those requirements and is an immediate hazard - traffic at 35 mph on one side, a curb drop and construction debris on the other. This is a stop-work condition for the pedestrian exposure.
First action: stop the exposure - restore a protected path or halt the work generating it - before anything else. Then notify the contractor's competent person and the engineer the same day, plus the agency's ADA/TTC coordinator. Document with photographs, measurements of the route width and slopes, and the times.
A protected temporary walkway or a barrier-separated pedestrian lane is the usual fix; tape and cones are not a pedestrian control.
3. What is your documentation and notification path for these deficiencies, given the closure runs through Friday?
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The inspector identifies, notifies, and documents; the inspector does not redesign the TTC plan.
Sequence:
- If there is an immediate hazard (workers in the buffer, pedestrians in the lane), have the exposure corrected that shift.
- Notify the contractor's supervisor and competent person in writing - a TTC deficiency notice listing each item: taper length, sign spacing, buffer intrusion, missing shadow vehicle, pedestrian route.
- Notify the engineer and reference the approved TTC plan sheet and the standard/typical number it was supposed to follow. Any deviation from the approved plan requires an engineer-approved revision.
- Record in the daily report: time of arrival, exactly what was found with measurements, who was notified and when, corrective actions and their completion times, and photographs.
- Confirm the fixes on the next shift - a written notice without a recheck is not closure.
For the balance of the week: the closure is in place daily, so recheck the setup each morning before work starts, including the pedestrian route, and confirm any night-time configuration separately.