Q: While proceeding east on the Henderson Bridge there is a sign for I-195 East that confuses me. Do I turn at the first exit even though the sign seems to be pointing forward to South Broadway straight ahead? How should I proceed? I usually enter I-195 E from Route 6. Please set me in the right direction.

L. D., Barrington

A: The sign you mention is located at the first exit on the Henderson Bridge when traveling eastbound, and reads “East 195” and displays a straight arrow. The definition and purpose of a directional assembly sign such as this one, according to the Manual on Uniform Traffic Control Devices (MUTCD), a Federal Highway Administration (FHWA) publication that sets standards and guidelines for traffic control devices, says a directional assembly, “shall consist of a route sign, a Directional Arrow auxiliary sign, and a Cardinal Direction Auxiliary sign, if needed.”

In the case of the Henderson Bridge the purpose of the arrowed sign is to supplement the signs for I-195 East located on Waterman Avenue prior to the Henderson Bridge. The signs on Waterman Avenue direct motorists onto the Henderson Bridge, while the sign at the first exit tells motorists to continue straight on the bridge, rather than exiting at that point.

These signs guide motorists to the last exit on the bridge, which leads to North Broadway in East Providence. From this point, motorists take a right turn onto North Broadway, and follow straight through until the intersection with Warren Avenue (Route 6) where they take a left turn onto Warren Avenue. Subsequently there is an on-ramp for I-195 East on Warren Avenue shortly after the intersection with North Broadway.

These signs were installed as part of the construction for the Washington Bridge project when the on-ramp to I-195 East located on Gano Street was closed. These signs would not typically be installed because access to I-195 East from the Henderson Bridge is not the nearest or most convenient point of access, however, when the on-ramp closed it was decided that the Henderson Bridge would be the best alternative to guide motorists to I-195 Eastbound from Waterman Avenue.

Lincoln Ave., Post Rd. intersection

Q: This deals with the intersection of Lincoln Avenue and Post Road during the afternoon rush hour. When you are coming to the intersection on Lincoln Avenue from Jefferson Boulevard and need to make a left and a quick right to get onto the highway, it is very difficult to do because the traffic is coming at you from the opposite direction (Lincoln Avenue from Wyoming Avenue) and is taking a right-hand turn, blocking any access for the traffic coming off Lincoln Avenue from Jefferson Boulevard. If the traffic coming off Lincoln Avenue from Wyoming Avenue were faced with a “No right on red arrow” where the arrow was only red during the couple of minutes the traffic coming off Lincoln Avenue from Jefferson Boulevard was making that left and quick right, it would be simply marvelous.

Jeannie B.

A: The traffic signal timing at the intersection of Post Road and Lincoln Avenue is comparable to other four-way intersections throughout the state. Both approaches on the side street (Lincoln Avenue) have the green light at the same time, causing the eastbound left turn and westbound right turn to proceed through the intersection at the same time.

Unfortunately for the eastbound left turns, and according to R.I. General Laws, the westbound right turn movement has the right-of-way. Therefore if there are a large number of vehicles taking a right turn from the westbound approach, it may be difficult to make a left turn from the eastbound approach.

RIDOT uses common engineering practices and accepted nationwide standards to determine cycle lengths and how the time is split between the intersecting roads. We take into consideration the traffic characteristics at the intersection such as traffic volumes, turning movements, crash data, and the percentage of truck traffic.

When the Department performs an analysis at an intersection using these characteristics we can determine the signal timing and its measure of effectiveness. The measure of effectiveness takes into consideration many factors such as fuel consumption and delay times. This gives the Department an idea of how effective the signal would be during different signal timing scenarios.

It is RIDOT’s practice to consider the overall operation of the signal rather than individual turning movements. Priority, however, is usually given to the main roadway when timing a traffic signal.

The timing and/or phasing of the existing traffic signal, or the configuration of an approach, cannot be changed without performing a traffic engineering study on the intersection, and having any changes approved by the State Traffic Commission (STC). A representative from the City of Warwick would need to submit a request to the STC to have this signal studied. The STC does not consider requests made by private citizens. Requests must come from the city, and consequently must be from someone who represents the views and opinions of the city as a whole (i.e., the police chief or a council member).

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.

Still lost? Find archived answers to past transportation questions at projocars.com.