​​Evening Peak-Hour Freeway Speeds (General Purpose Lanes)​​



Congestion in Metro-Atlanta causes travelers to anticipate delays and allow for additional time when traveling during peak evening hours (3 PM – 7 PM). The goal is to reduce congestion such that a 30 minute trip during non-peak travel hours would take no more than about 40 minutes during peak hours. Likewise, a speed of 55 mph during non-peak hours would be reduced to about 40 mph during peak hours. This measure tracks average speeds across the most congested freeways in the Metro Atlanta region. By focusing on these key roadways, GDOT can identify and address the biggest challenges to congestion in our region.

Strategic Objective

Optimize the throughput of people and goods on network assets throughout the day. GDOT has set a peak hour target of 40 mph or better for the Interstate General Purpose (GP) lane system.

Road to Improvement

GDOT fell short of its 2017 target, achieving an average peak hour speed of 33 miles per hour. In 2017, GDOT opened the I-75 South express lane system. This project not only provided reliable speeds for users of this system, but it also indirectly benefited motorists in the general purpose lanes. Similar improvements are expected upon opening the northwest corridor project in CY 2018. GDOT has also begun the initial planning and design work for the Major Mobility Investment Program (MMIP). Over the next 10 years, the pursuit of this program is expected to dramatically improve travel conditions and speeds within the Metro Atlanta region. In addition, commute options such as teleworking, carpooling, vanpooling, and transit can also help relieve congestion.

Travel Time Index

Another way to evaluate the effect of congestion is the Travel Time Index (TTI). The TTI is the relationship of travel time in the peak period to travel time at free-flow conditions. A Travel Time Index of 1.30 indicates that a 20-minute free-flow trip will take 26 minutes or 30% longer in the peak period. Click Here for more information on Travel Time Index.​​

Disclaimer: The Georgia Department of Transportation makes no representation or warranties, implied or expressed, concerning the accuracy, completeness, reliability, or suitability for any particular purpose of this information and data contained on this website.