In 2003, the Average Daily Traffic (ADT) along I-93 ranged from 77,000 vehicles per day north of Exit 5 in Manchester to 114,000 vehicles per day south of Exit 1 in Salem. In addition to the high ADT, traffic incidents have occurred regularly on the stretch of I-93 from Salem to Manchester. The incidents vary in severity, from debris on the interstate to overturned tractor-trailers, causing motorists to seek detours on local streets, spreading congestion onto the parallel roads. It is evident that a corridor-wide traffic incident management solution has become increasingly critical to keep people and goods moving. The NHDOT, in cooperation with the Federal Highway Administration (FHWA) and regional stakeholders, has sponsored the development of the Interstate 93 Corridor Traffic Incident Management Plan (I-93 TIMP). The implementation of this plan and the state's Quick Clearance policies will help to make the I-93 corridor a safer road.
Over the past few years, training workshops and meetings have been conducted with state and local stakeholders to solicit their input on the needs and opportunities seen in the corridor. A multi-disciplined IM Work Group of NHDOT staff was tasked with developing an action plan using the feedback gathered from these sessions. The plan was drafted and reviewed with the Technical Steering Committee (TSC), a committee comprised of local emergency responders (see Strategy 1.9 below for more details). The Traffic Incident Management Plan (I-93 TIMP) was adopted by the DOT and local communities in March, 2008. The I-93 TIMP establishes the following goals:
The action plan is intended to document the traffic incident management needs of the corridor and provide a detailed outline of specific strategies for meeting those needs. The following strategies were determined as key to achieving the stated goals
The following is a brief explanation of these strategies. For more detailed information, see the I-93 TIMP adopted in March 2008:
Implementing the use of Service Patrols was identified as a highly beneficial tool to reduce the potentially significant impacts and major delays caused by otherwise minor incidents. The patrols were implemented beginning May 1, 2008. The program is operated during the heaviest traffic volume periods of the morning and afternoon commutes, making a continuous loop on I-93 between Exit 4 in Windham and Exit 47 in Methuen, MA, stopping for all incidents encountered. Response to minor incidents such as changing flat tires, providing gas or water, or clearing debris from the roadway is being provided.
ITS refers to a broad range of diverse technologies applied to transportation. The first ITS technologies deployed on I-93 were in the Exit 1 area, and included traffic sensors, a traffic camera, and variable message signs. ITS technologies have since been added to the Exit 3 and Exit 5 construction areas. The message boards are controlled and monitored through the Department's new state-of-the-art Traffic Management Center (TMC) in Concord. Information from the TMC is broadcast on the internet so that motorists, TV and radio stations can access the information via websites at any time. The traffic cameras and detecting equipment give the NHDOT real time information about how traffic is behaving on the roadway, alerting the DOT and emergency responders to incidents as they occur, allowing for a quicker response time. The variable message signs are used to provide the motoring public with actual travel times and notification of any traffic stops or delays.
Additionally, Roadway Weather Information Systems (RWIS) alert the Department and its road maintenance personnel to potential icing conditions along the roadway, allowing them to more effectively apply de-icing materials to the road.
NHDOT Traffic Management Center
A coordinated response to incidents is dependent on timely and accurate information. Deployment of ITS technologies and the creation of the Traffic Management Center (TMC) have provided the ability to communicate traffic incident information to motorists, thus reducing congestion and delays, and enhancing the response to and the mitigation of incidents. Protocols are being fine tuned as more ITS devices are deployed.
The Department worked with the Technical Steering Committee (TSC) consisting of representatives from each town within the corridor and Methuen, MA, as well as representatives from the NH and MA State Police, to establish planned emergency routes that can be used during incidents on I-93. The purpose is to allow as much traffic as possible to bypass a section of the interstate that is affected by an incident. It is a proactive approach to more safely and effectively managing incidents on the highway and reducing the occurrence of secondary incidents. The emergency routes are not intended to be used as a means of facilitating construction, but only when there is an incident requiring closure of the highway. This will help to minimize the backup of traffic on the interstate and facilitate the flow of traffic on secondary roads, thus reducing the probability of secondary incidents. By August 2008, the emergency routes will be permanently signed and will provide routes that travelers can follow once they are directed off the highway. See links below.
It is anticipated that each major reconstruction project on I-93 will require an Individual Work Zone with its own Management Plan, while smaller projects may be combined or included in another work zone TIMP. Successful plans will result in minimizing traffic disruption by enabling efficient clearing of incidents, removing construction restrictions on the highway, increasing responder safety, reducing the potential for secondary incidents, and fostering interagency cooperation prior to and during an incident in the work zone.
The NHDOT has worked with local communities to identify tactics to ensure access to the highway and to a water source for emergency responders. These efforts resulted in establishment of emergency access points for vehicles, water access points for fire hoses through right-of-way fencing and sound walls and on bridges, and maintaining highway median turnarounds. These measures will improve response time, reduce impacts on the traveling public, and reduce the probability of secondary incidents.
An MOA is a written document developed and executed between parties to establish ground rules for working cooperatively together to meet an agreed upon objective. As effective IM throughout the I-93 corridor will require a cooperative effort between state agencies, local communities and private entities, MOAs will provide the means for one jurisdiction to provide resources or support to another, and to facilitate the timely delivery of assistance during incidents.
A Public Outreach Campaign was launched concurrently with the beginning of construction at Exit 1, and is proactive in informing the public of upcoming construction activities, disseminating information about TIMP strategies, and providing information regarding traffic conditions. POC-related materials are posted to this website and distributed in hard-copy format at public meetings.
As part of the I-93 project, the NHDOT recognized the need to formalize a working relationship between the Department, other state agencies, local communities. The DOT also recognized that the TSC should be led by local communities, as having local leadership is critical to ensuring local support and long-term sustainability. The DOT provides technical support on highway infrastructure and operations initiatives. Members include representatives from police, fire/EMS, and public works from Salem, Windham, Derry, Londonderry and Manchester, as well as the NH and MA State Police, and FHWA.
Establishing a formal post incident review procedure is encouraging the practice of reviewing actual incident responses soon after they have occurred. The reviews help to identify the operations that worked well and should possibly be used more often, as well as those that didn't work as well and how they could be improved. Properly conducted reviews are effective ways to foster better cooperation between the various response agencies and will become a key part of a sustainable traffic incident management program for the corridor.
The DOT will be upgrading the mile marker signs to meet current standards. The new markers will be installed along the entire corridor prior to mainline reconstruction. Having accurate location information will reduce the response time of emergency responders.