Yes. The Highway Capacity Manual is a compendium if work by the traffic engineering professionals that examines data and observations to develop theories and ap

Yes. The Highway Capacity Manual is a compendium if work by the traffic engineering professionals that examines data and observations to develop theories and approaches to traffic. If you have a freeway with no on ramps nearby (usually 6 miles) then you should be free of traffic issues if the roadway throughput (1,500 per lane per hour), if it goes above that then crazy agents in the traffic do not allow for distances between vehicles and the brake of one individual creates a cascading effect. This is one cause of back ups. The next is if you have an on ramp on said freeway, there must be enough capacity for the freeway to absorb those vehicles in. Additionally, you need to have space and time for the vehicle to merge in. If the driver does not feel safe or have enough distance, they will perform erratic moves to get on, which will slow down traffic in the aforementioned cascade. If a highway on-ramp is failing, it is usually due to a political person pushing for it. The Federal Highway Administration (FHWA) has a long list of requirements for a new ramp, and they are very well thought out to prevent issues and are good to work with.