I have several questions.

1. Why were all the signs on I-95, with posts and bases, replaced? They look the same as the old ones and most are in the same place.

2. At the same time, there is a tall pole with some sort of device on top installed at each exit. What are they?

3. In the last few years, at Exit 3, there have been many light poles replaced and new underground wiring installed. There are still no lights on at night at this exit. When will they be turned on?

We are replacing sign panels as well as posts and bases on Interstate 95 for several reasons. The sign panels that were recently replaced were originally installed in 1986. All of our signs have reflective sheeting to increase the visibility of the sign at night. Typically, the life expectancy of the reflective sheeting on these sign panels is 7 to10 years. The sign panels that we recently replaced were over 20 years old and we very difficult to read at night.

The posts and bases that were also replaced with the sign panels had also passed their life expectancy. When the sign panels were replaced in 1986, most of them were installed on the existing posts, which were built in the 1960s. Typically, the life expectancy of these posts is 25 to 30 years. Because of this as well as new standards that have been adopted since the 1960s, RIDOT replaced them along with the sign panels.

The tall poles with a device on top installed at each exit are highway monitoring devices. They are cameras that allow the Department to monitor the traffic as well as any traffic incidents that may occur. For example, if there is a crash, and we can see it on the camera back at the Department, then we can notify the police, which decreases the overall response time to the incident. The decreased response time could be critical if a motorist is injured, and it also aids in clearing the highway faster, reducing congestion. We can also share this information with those already on the road by using roadside and overhead message boards, the 511 system, 1630 AM Highway Advisory Radio, and even the Internet.

National Grid is working to restore the lighting on I-95 between Exits 1 and 4. They tell RIDOT that they are currently are working on Exit 2.

Dana Alexander Nolfe, chief public affairs officer for the state Department of Transportation, has agreed to answer questions of general interest posed by Journal readers about state roads and other state transportation matters.

The DOT is responsible for the state’s transportation infrastructure, which includes highways, bridges, traffic signals and bikeways.

To ask a question that would also be of interest to other readers, send a letter to Ask RIDOT, Features Department, The Providence Journal, 75 Fountain St., Providence, RI 02902. You can also e-mail your question to projocars@projo.com. Please put “Question for the DOT” in the subject field.

Questions or complaints of a specific nature should be posed to the DOT directly and will not be answered in this column.