Six Lane I-65

[Indyroads]

The congestion on the freeway is not at critical mass yet right now LOS levels are probably at C and D levels at peak periods. but D isn't an acceptable level of service.

Per FHWA, D is considered acceptable.  Your local policy may vary...

Looking at the LOS 4 information that still seems like a fair amount of congestion is acceptable to the FHWA. To design roads to barely meet acceptable standards doesn't make sense, because they will likely drop below a LOS D very easily with just a moderate increase in volume. not to mention the road grinding to a complete halt during any sort of road incident. At least with 3 lanes it will reduce the likelihood of incidents and also allow traffic to flow through in the event of an incident.

[Alps]

The congestion on the freeway is not at critical mass yet right now LOS levels are probably at C and D levels at peak periods. but D isn't an acceptable level of service.

Per FHWA, D is considered acceptable.  Your local policy may vary...

Looking at the LOS 4 information that still seems like a fair amount of congestion is acceptable to the FHWA. To design roads to barely meet acceptable standards doesn't make sense, because they will likely drop below a LOS D very easily with just a moderate increase in volume. not to mention the road grinding to a complete halt during any sort of road incident. At least with 3 lanes it will reduce the likelihood of incidents and also allow traffic to flow through in the event of an incident.

LOS depends on context. In NJ, LOS 'D' is fine, and sometimes we settle for LOS 'E' or even 'F' for certain movements because we just can't do better without spending hundreds of millions. In Nebraska, 'C' is cause for concern.

[froggie]

Looking at the LOS 4 information that still seems like a fair amount of congestion is acceptable to the FHWA. To design roads to barely meet acceptable standards doesn't make sense, because they will likely drop below a LOS D very easily with just a moderate increase in volume. not to mention the road grinding to a complete halt during any sort of road incident. At least with 3 lanes it will reduce the likelihood of incidents and also allow traffic to flow through in the event of an incident.

It should be noted that while LOS D may "seem" congested, traffic still moves at/close to the posted speed at LOS D.  LOS E is where you start to have the potential flow breakdown issues you describe.  Also, given traffic trends over the past 10 years, it would require a very detailed analysis to determine projected traffic levels...this would include current and expected land use and other possible transportation improvements, including non-freeway improvements.  The old adage of traffic increasing x% amount per year just doesn't apply anymore.

It should also be noted that, unless you have a VERY LIGHT load of traffic, any crash can tie up a multi-lane highway.  I have seen far too many cases in my time of freeways with 3 and even 4 lanes per direction moving free-flow, and then suddenly bottling up because there was an "incident" on the shoulder, not even blocking a lane.  Bad driver habits are often the root of this, not a lack of lanes.

[trafficsignal]

For what its worth, INDOT's criteria gives a minimum LOS C for rural interstate design projects.  Urban reconstruction is allowed to be D.

I'm of the opinion to widen where it makes sense, but not to spend the money widening just to make 65 & 70 6 lanes across the whole state.  That kind of policy seems to be driven by politicians more than data.

[31E]

I drive on I-65 in Kentucky and Tennessee a lot, and the six-laning in Kentucky has been a tremendous improvement. From the Kentucky border to Nashville it's just four lanes, there's too much traffic to pass slower vehicles most of the time, and traffic is slowed down and jammed up a lot. From the Kentucky border north to Bowling Green traffic flows so much better; traffic is pretty much never slowed down or jammed up. In the Nashville to Bowling Green stretch, I've seen many accidents cause traffic to slow to a crawl in Tennessee, but I've never seen that happen in Kentucky. Free flowing traffic has more breathing room in the event of a lane blockage than traffic flow that's barely adequate to start with.

I have less experience with I-65 north of Louisville but chances are if it's being considered by IDOT in long-term plans it needs to be done right now . In a civilized country traffic on rural freeways should flow freely, considering that rural roads are the cheapest and easiest kind of road to upgrade to achieve free flow conditions. If you can't even achieve free flow where it's easiest to do so, you're in really bad shape.

LOS depends on context. In NJ, LOS 'D' is fine, and sometimes we settle for LOS 'E' or even 'F' for certain movements because we just can't do better without spending hundreds of millions. In Nebraska, 'C' is cause for concern.

Interesting; it's only logical that rural states would be less used to congestion and have less tolerance for it, and fortunately for them it's easier to fix congestion in a rural state. A reasonable expectation when a person drives on a road (as opposed to a parking lot) is to be able to travel at the posted speed limit and have enough room to maneuver, which would correspond to LOS 'C'. Nothing less than that should be accepted; obviously that takes a commitment from the whole government, not just the DOT (*cough* funding *cough*), but lowering your expectations will only lead to worse results. What I'd shoot for as a minimum would be B for rural freeways and C for urban freeways.

[froggie]

However, as Steve noted, it's often not feasible to shoot for such level-of-service.  At some point you have to draw the line between higher level-of-service and construction/right-of-way/maintenance costs.  Is it really worth widening a road that may see platoons of traffic, but traffic that still moves close to the speed limit, when the cost of that widening is tens of millions of dollars (which could go a long way towards bridge repair...LOTS of bridges nationwide that need that), or takes out acres of wetlands (which has father-reaching implications than most people realize...from water quality to flood mitigation), or wipes out homes and businesses...land that is contributing tax revenue to the local jurisdiction?  This is a question that needs much more detailed analysis with DATA than some people's driving perceptions.

[Scott5114]

It should be noted that platooning has been considered dangerous behavior on freeways since the 60s (I have a driving manual from the mid 60s which stresses, with diagrams, that good driving policy is to drive between the platoons wherever possible). Thus if an expansion might not make sense from a pure LOS point of view, there may be a safety argument to be made. 

[froggie]

If there is a crash issue, yes....crash data would be factored in during the detailed analysis I cited earlier.