Thursday, October 4, 2007

INDOT freeway design

Why does INDOT design multi-lane entrance ramps so that the interior entrance lane merges with a through lane on the mainline? A couple of examples that come to mind are NB 465 to NB 69 and NB 465 to NB 65 on the northwestside. This seems completely unsafe. If there is a vehicle at the same point in each lane, the alternative to a collision would be to maneuver into another lane, which might also be occupied a vehicle. Why wouldn't the entrances be designed so that the outside entrance lane eventually merges into the inside entrance lane? In that case, if there were a conflict at the merge point, the vehicle in the outside lane, which would be responsible for merging, would be able to maneuver onto the shoulder where there shouldn't be another conflict. I'm not a traffic engineer, but I've not seen such a design anywhere else in my travels except for Indiana.

This type of unsafe design is not limited to INDOT though. The City of Indianapolis employs a different, but similarly dangerous merging design. SB College Avenue, approaching Interstate 65 drops from two lanes to one, as does NB College, just north of 71st Street. But rather than having the right lane merge into the left, the streets are signed and striped to require the interior (left) lane to merge to the right. It would seem that in the event of a conflict between two vehicles traveling the same direction, this design would make it more likely that a vehicle in the left lane might drive into oncoming traffic especially given the lack of a raised median at either location. Again, I haven't seen this design anywhere other than Indy.

On another note, why does INDOT insist on using mile markers to describe the location of a traffic incident on their overhead changeable message signs in the metro area? How many of us have any idea where MM 107 is on any particular Interstate? I can understand using the mile marker when you're describing an incident ahead on the same roadway. (If you're on I-65 and the sign reads "Accident- Stopped Traffic at MM 32" it's pretty easy to read the markers along the side of the road to identify the location of the incident.

But consider you're traveling north on I-65 at Southport Road and the sign reads "Lane Closed EB I-70 at MM 82 Expect Delays". If you don't know where MM 82 is, you won't know if this is between I-65 and I-465, or if it's 20 miles east of I-465. The information isn't helpful if you don't know whether the incident is on your planned route. Wouldn't it be more informative to indicate "at Emerson", "at Shadeland", at "Mt Comfort", "at Greenfield" etc.? It sure would be to me.

Finally, I'd like to comment on the Super 70 project with the following two observations: First, the lack of any real increase in traffic on Michigan and New York Streets on the near eastside solidifies my opinion that these city streets no longer need to serve as urban freeways from the far-eastside to downtown. The time has come for these streets to revert to two-way traffic. The first benefit would be to slow traffic down, thereby increasing the livability of the neighborhoods adjacent to these streets. The noise from traffic would likely decrease as speeds decreased. The traffic that utilizes these one-way streets typically proceeds faster than traffic on two-way streets in the city because the current multi-lane design of the streets and the lack of congestion encourages higher speeds. Second, commercial redevelopment would be more likely to occur because businesses would have the advantage of being visible and accessible by traffic in two directions, with a peak of drivers both in the morning and in the afternoon/evening.

My other observation was of disappoint as I drove south on Sherman Drive from the Brightwood neighborhood and stared upon the new freeway overpass. The one benefit Brightwood had was that when I-70 was constructed it was channeled under Sherman Drive thereby deflecting traffic noise away from the neighborhood. The I-70 corridor was so narrow (even though it still accommodated the same eight travel lanes that the overpassed version will carry) with development on either side, that you could actually cross the Interstate and not even realize it. No more. Now, the Brightwood area to the north, as well as the area to the south, will experience the same hum of freeway noise with which most every neighborhood adjacent to a freeway must cope. Unfortunately for Brightwood, this headache won't come with the benefit of improved access to/from the freeway.

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