Baltimore County Now
Engineer I, Public Works, Bureau of Traffic Engineering
Around 350 traffic signals are maintained by the Baltimore County Bureau of Traffic Engineering. Part of maintaining the signals is determining and programming signal timings to ensure that there are appropriate green times for the assigned movements so that traffic may flow efficiently. Traffic engineers determine the signal timings with assistance of a computer program called Synchro.
Synchro is a computer program that calculates the Level of Service (LOS) of an intersection based on traffic volumes, lane geometry and signal timings. Traffic volumes at an intersection are collected on one-year or three-year cycles depending on the severity of congestion. This traffic intersection data can be viewed on the County’s web site. The most heavily congested intersections are counted every year. At the same time, traffic engineers also verify the lane geometries and signal timings. If there is a proposal to change lane geometries, such as adding turn lanes or installing a roundabout or traffic signal, Synchro can determine if the proposed changes will improve the traffic flows at the intersection.
Because growth is natural and expected in metropolitan areas, traffic signal timings need to be revised from time to time to accommodate the change in traffic demands based on increases that are apparent from the traffic counts. Synchro is used to determine if signal timing changes are needed. However, achieving the lowest delay at a particular intersection does not necessarily represent the optimal signal timing, especially at coordinated signals, because the main objective is to move traffic through the corridor. In coordinated signal systems there is more green time given to the mainline traffic. Synchro can analyze a series of coordinated intersections and plot out a graph that shows how traffic flows from one intersection to the other. In addition, Synchro has an auxiliary program called Sim Traffic that can help visualize traffic flows.
Sim Traffic is a simulation software that takes data parameters from Synchro and puts them in an animated presentation. Roads and intersections are laid out in relative scale in top view, with simulated cars running through the intersections. Because flows from signals in a coordinated system are dependent on one another, it is good to see in action how the queues dissipate and move through the corridor, and where congestion tends to build up. Like the applications used in Synchro, we can also see how different lane geometries and signal timings affect the flow of traffic.
We can also make a comparison on the effectiveness of a proposed signal or roundabout at an existing intersection. This is very helpful because the animations visually show whether the changes create more congestion or improve traffic flow which can be very helpful when explaining traffic engineering decisions to the public.
Although Synchro and Sim Traffic are very helpful in determining timings, they are not a substitute for field observations. Ultimately, a field observation is necessary to verify improvements from timing changes, and further adjustments to timings will be done based on field observations. Synchro and Sim Traffic are not substitutes for engineering judgment; however they are great tools in the traffic engineer's tool box.
Baltimore County Director of Public Works
Every once in a while you’ll hear in the national news about how our country is struggling to do basic maintenance and upgrade critical infrastructure like bridges, roads and water and sewer systems. Here in Baltimore County, thanks to strong fiscal management and a proactive approach to basic maintenance, we are working hard to keep our systems in good working order and ensure the safety of the public.
These maintenance and repair projects are great real-world examples of why it matters that the County is repeatedly awarded the highest possible bond rating. We are one of only 39 counties in the entire United States with a triple triple-A bond rating. Basically, it costs us less to finance important capital projects, so we are able to do more of them.
I am proud of the Administration, as well as the employees and contractors of the Department of Public Works, who have taken strides toward bringing the County's infrastructure into the 21st century - improving, rebuilding, modernizing and replacing bridges, roads, water mains, reservoirs, pumping stations, storm drains, sewer lines and man holes. At Public Works we strive to run our department based on common sense, accountability and compassion.
Here’s a quick overview of the County’s investment over the past three years:
$115.5 million for water projects, from FY 2011 to FY2013
$8.7 million to clean and line pipes
$35.9 million to lay new water pipes
$7.7 million for new pumping stations and storage tanks
$63.2 million to fund City/County facilities: reservoirs & treatment plants
$11 million to reline sewer pipes
$5.3 million for new sewer lines
$47.8 million to rebuild 20 pumping stations
$76.5 million to fund City/County facilities, including treatment plants
$87.5 million for design, modeling, studies, and investigation
$5.6 million to replace 7 bridges
$7.8 million to repair 5 bridges
$0.6 million for 2 wetland projects
Road Construction, Sidewalks & Alleys
$44.1 million 25 projects including:
$17 million for Owings Mills Boulevard
$7.5 million for Cherry Hill Road
$2.2 million for alleys
$19.6 million to inspect 676 miles of pipes & manholes with video/other methods
$4.6 million to clean 1,575 miles of pipe
$9 million for the Central Acceptance Facility Transfer Station
$14 million for Central Acceptance Facility Single Stream Recycling System
$6 million to cap the Hernwood landfill
$.43 million for Parkton Landfill remediation
$1.5 million for Hernwood Landfill remediation
$12.1 million for Eastern Sanitary Landfill remediation
$41.8 million to pave 220 miles
$8.2 million to install 67.5 miles of curb and gutter
$3.1 million to replace pipes and inlets for 36 projects
$1.2 million to design and install new drains and inlets for 25 projects
$1.3 million to fund flood studies, to locate utilities and computer support
$.75 million for new and replacement traffic signals (includes new battery backups for 10 intersections)
$.25 million to provide traffic calming in 93 communities
$ 4.1 million to paint 3500 miles of road lines and install and maintain 22,700 signs