Contracting methods for work zone ITS have seen some very interesting developments over the past year or so. Several states have chosen to bid this work outside of the project contracting process. Each has its own set of advantages. Today we will discuss those and, I hope, give you some ideas for your own state.
We are just talking queue warning systems at this point. All of these states began there, which makes sense. 26% of all work zone fatalities are as a result of end of queue crashes. But there is no reason we can’t specify other systems such as dynamic merge or travel time or trucks entering with a similar approach. Since these systems share most components in common, this will drive the cost down even further.
Let’s begin with what these state processes have in common. All of them contract work zone ITS outside of the normal project bid process. The systems are not line items in a larger job. Instead, the state DOT has a contract (or contracts) directly with local traffic control companies to supply, install, maintain and remove work zone ITS systems or components. Think of it as an A&E contract.
So far these contracts are all for some combination of traffic sensors and changeable message signs. In most cases they also include the central control software and data archiving. The winning contractor must supply and install equipment as needed, usually within a few hours.
There are several obvious advantages:
• Immediate availability of portable ITS assets and data.
• Ability to use these systems when and where they are needed, even for incident response or special events.
• Traffic operations department knows where they expect problems and assigns assets as needed.
• When systems aren’t needed, it costs the state nothing.
• When needed, these are reimbursable under the Highway Safety Improvement Program at 90%.
• There are no minimums so contractors are motivated to respond quickly so as to earn more work.
• Construction and design folks need not learn about work zone ITS.
Texas (TTI) Model
The first to do this was Texas. They had several major projects planned for the I-35 corridor and asked the Texas Transportation Institute to find ways to prevent rear-end crashes in what they knew would be frequent stop and go traffic.
Because they were the first state to try this and bidders had no way of knowing what would happen, the state purchased the equipment and local traffic control contractors bid the work of installing, removing and maintaining the equipment. Each day TTI looks at planned lane closures, estimates the queue lengths, then calls the contractor and tells them which systems are needed and where. They call out either a type 1 or type 2. A type 1 is 4 sensors and 1 changeable message sign. A type 2 is 8 sensors and 2 CMS.
Advantages: TxDOT pays only for the labor to deploy and maintain the equipment. This method is easier for contractors to bid. They know their labor costs, etc. Whereas work zone ITS system costs are new to most and may be bid on the high side to cover unforeseen expenses.
Minnesota / Iowa Model
For this model, the state contracts with a single equipment rental company to supply, deploy and maintain microwave sensor trailers. The sensors are integrated into the states permanent sensor network. They are used for systems operations functions as well as project specific systems such as queue warning.
Advantages: Seamless integration with permanent assets. Sensors can be quickly relocated as conditions change. Wavetronix sensors provide far more detailed data including lane by lane counts, classifications and volumes. However, they are significantly more expensive than doplar radar.
Illinois provided the most recent approach to this process. They chose to bid sensors and message signs by the day, week and month delivered within a district. It includes the central controller software and data archiving.
Advantages: This gives local contractors an advantage which will reduce response times to the state.
The state only pays when they order devices. There are no minimum orders. This motivates the contractor to perform well in hopes of getting more work.
In recent weeks several other states are adopting these methods including Indiana, Michigan and Oregon. All three approaches are working well in the states where they are used. The best one for your state will depend on your needs and the underlying contracting regulations you must work within.
Good specification writing is important. You must describe exactly what outputs are required: how system should operate, data access and storage, response times for delivery and set-up, response times for maintenance, repair or damage, etc. Be sure to list the required number and type of each device that the contractor must have in stock and ready to deploy.
You should also consider some sort of prequalification process. It should give a score for financial stability, years in business, and experience with work zone ITS deployments. Prior experience should also be considered for future contracts – both positive and negative.
Keep it simple. You may want to include portable cameras. Or you may want to include separate numbers of microwave and doplar sensors. But don’t get into other devices you aren’t likely to need. The contractor will know these are unlikely to be used much and so will have to bid high to cover their fixed costs.
This new approach makes using work zone ITS far easier to do. It probably saves money as well. It can jump start the use of these systems in your state, so pick the model that fits you best and get started!