What is the Max. Speed diffierential allowed between to speed limit signs?

[fff35]

I am in Dublin, Ohio. What is the Max. Speed diffierential allowed between to speed limit signs? My road goes from 25mph to 45mph back to 25 mph in a 1.5 mile span. Is this legal?

 

[racer72]

I am in Dublin, Ohio. What is the Max. Speed diffierential allowed between to speed limit signs? My road goes from 25mph to 45mph back to 25 mph in a 1.5 mile span. Is this legal?

Speed limits are set by traffic engineering analysis. You can visit the traffic engineering department for the jurisdiction and ask to see the analiysis for that particular stretch of road. It will state the purpose for the reductions in speed limits in a relatively short distance.

 

[CraigFL]

We have speed limt signs that go from 45mph to zero(stop sign) back to 45MPH in less distance than that. It is up to the traffic engineers but I'm sure there aren't too many wrong cases....

 

[Pugilist]

I agree, except...

Here in CA, most speed surveys (engineering analysis) have been conducted in an improper, illegal, unprofessional manner - in order to obtain a low speed limit demanded by political forces. The surveys/analysis falls apart under the slightest scrutiny. I am sure it is the same everywhere else, or worse. So, find out what the rules are for surveys/analysis, and see if those have been followed.

Pug

 

[WindyAruba]

Agree with Pug on this...It is unlikely that the 25 mph speed limit is based on actual warrants in this case....


Section 2B.13 Speed Limit Sign (R2-1)

Standard:
After an engineering study has been made inaccordance with established traffic engineering practices, the Speed Limit (R2-1) sign (see Figure 2B-1) shall display the limit established by law, ordinance, regulation, or as adopted by the authorized agency. The speed limits shown shall be in multiples of 10 km/h or 5 mph.
Guidance:
At least once every 5 years, States and local agencies should reevaluate non-statutory speed limits on segments of their roadways that have undergone a significant change in roadway characteristics or surrounding land use since the last review.

No more than three speed limits should be displayed on any one Speed Limit sign or assembly.

When a speed limit is to be posted, it should be within 10 km/h or 5 mph of the 85th-percentile speed of free-flowing traffic.

Option:
Other factors that may be considered when establishing speed limits are the following:

1. Road characteristics, shoulder condition, grade, alignment, and sight distance;
2. The pace speed;
3. Roadside development and environment;
4. Parking practices and pedestrian activity; and
5. Reported crash experience for at least a 12-month period.

Two types of Speed Limit signs may be used: one to designate passenger car speeds, including any nighttime information or minimum speed limit that might apply; and the other to show any special speed limits for trucks and other vehicles.

A changeable message sign that changes the speed limit for traffic and ambient conditions may be installed provided that the appropriate speed limit is shown at the proper times.

A changeable message sign that displays to approaching drivers the speed at which they are traveling may be installed in conjunction with a Speed Limit sign.

Guidance:
If a changeable message sign displaying approach speeds is installed, the legend YOUR SPEED XX km/h (MPH) or such similar legend should be shown. The color of the changeable message legend should be a yellow legend on a black background or the reverse of these colors.

Support:
Advisory Speed signs are discussed in Sections 2C.36 and 2C.46 and Temporary Traffic Control Zone Speed signs are discussed in Part 6.