Sunday, January 30, 2011

The Revised Arch Ground Plans

If there is one good thing that comes out of this project, it will be the flipping the half diamond interchange on I-70 near the Eads Bridge. Currently the first exit available for those traveling westbound after Memorial Drive is up at Madison Street, 1.69 miles later (slightly less for those coming from I-70 off the PSB, slightly more for those coming from I-55. The new ramps will reduce the distance to around 0.6 miles. Better than the current design, especially for cross river traffic, but ideally it seems there should be another exit before Madison Street - which doesn't seem like the best place for an exit anyway; Cole Street or Broadway seem like superior locations.

In the past there used to be a full interchange for the MLK Bridge, but the westbound exit and eastbound entrance seem to have been removed sometime before 1988. I am guessing these ramps were removed due to weaving issues with the current ramps to/from Memorial Drive at the north end of the depressed section.

One advantage of the revised interchange is the Eads Bridge finally gets decent interstate access on at least one side, making it a somewhat better alternative to the PSB, although it could use some access improvements on the Illinois side. The current design can make exiting or entering I-55/64/70 somewhat tricky for destined for or coming from I-55/70 due to weaving with I-64 traffic. This could be fixed however with a new half diamond on the Illinois side right at Broadway.

As for possibly changing the Eads Bridge from 2x2 to 1+reversible+1, I would like to see more traffic data before fulling endorsing this idea. The Eads Bridge is currently underutilized, but the improved interstate access on the west side could change this.

Depending upon the alignment of the modified Third Street between the Eads Bridge and Laclede Landing Boulevard/Convention Plaza, access could get easier or harder for northbound traffic wanting to access the MLK Bridge. The most recent presentation document (see http://www.cityarchrivercompetition.org/wp-content/uploads/2011/01/MVV_Public_Presentation_1_26_11.pdf) does not give a detailed view of the area to see if there will be any changes to the intersection with the MLK Bridge. If there are not, given the current intersection design and the diagram of changes on Page 24/36 of the presentation, MLK Bridge access will require cutting west to Fourth Street, since the provided drawing does show the connector between Morgan and Convention Plaza being removed.

This is one area that could use some changes, both now and in the proposed plan. One option would be to go with the proposed plan, but leave the Morgan - Convention connector, and even make it two way. Another, maybe less optimal option would be to realign Convention Plaza to directly align with Morgan Street, align Third Street so it has access to the MLK Bridge, and shift Southbound Memorial Drive to create a four-way intersection at Morgan Street. The whole MLK Bridge area would be best revisited though after the new I-70 bridge opens, when it can be confirmed how much traffic will shift to the new bridge.

One area of the new plan that is disagreeable is narrowing Chestnut and Market Streets. Chestnut is already two through lanes plus two parking lanes (and without a median, despite what the drawing on Page 9/36 says), with a curb to curb width around 36 feet around Seventh Street (estimated from Google Earth). It does seem to widen to around 42 feet elsewhere however. Narrowing Chestnut by 15 feet by removing the south lane could easily get one trapped behind someone trying to parallel park. Depending on the design for Market, the same issue could arise for westbound traffic.

Another area that may be lacking is not revising the I-55 interchange around Seventh Street. The PWP proposal would have made it easier for traffic to divert around a reduced Memorial Drive with better access to/from I-55 around Seventh Street. The current design does not seem to compensate for removing/downsizing Memorial Drive between Market and Pine. Maybe if the traffic study would be made freely available online I would be more convinced that the adjusted I-55 access is not needed.

As for the gondolas? I would rather see a new pedestrian bridge parallel to the PSB, or a new pedestrian walkway on a replacement of the PSB.

Monday, January 17, 2011

Missing Movements 1, Part 2: Improving Access Between Northbound I-55 and Westbound I-64

In Part 1 I decided the most reliable yet fastest route to access Westbound I-64 from Northbound I-55 was to take I-44 west to the Grand Exit, double back to Compton, then head north to access I-64 from Market Street. I did not recommend the supposedly faster Kingshighway route due to possible delays from the railroad crossing on McRee Avenue, or the Hampton Avenue route due to possible delays from Forest Park traffic. In this post I will look at some options for decreasing the time between Northbound I-55 and Westbound I-64 from added new ramps to completion of MO 755. In addition, I will look at one former option that was deconstructed.

Remember that to the best of my knowledge, all but one of these are options are not being planned or considered by any agencies in charge today (and I'm not sure how alive the one possibly being considered is anymore).

Former Option: Exit I-55 at Lafayette, head west on Lafayette to 14th Street, then proceed north to access I-64 from the ramp near Cark Street

Before the Truman Parkway was built, 14th Street was four lanes between Lafayette Avenue and Chouteau Avenue. There was a stoplight at Park Avenue, and a stop sign near the school on the east side of 14th Street. The speed limit was 35 miles per hour, except for a "When Children are present" 25 miles per hour school zone near the school. Today 14th Street between Lafayette and Chouteau is two lanes with a median and a speed limit of 25. The stoplight at Park Avenue has been replaced with a roundabout, and the stop sign near the school has been replaced with a pedestrian stoplight.

I don't remember the exact speed limit on Lafayette between the I-55 ramps and 14th Street, so for here I am assuming it was 30 miles per hour.

The 14th Street route is 7.06 miles long. In the old days it would have taken around 8.55 minutes to transverse nonstop, or 12.14 minutes accounting for stoplights and stop signs (remember that I am counting travel time beyond the route between the interstates, not just the time taken getting from Northbound I-55 to Westbound I-64; in addition, I'm assuming here it is traversed when the school zone speed limit is not in affect). This time puts it near the middle of the pack of options.

Nowadays this route would take 12.47 minutes to transverse(I'm assuming the same delay at the roundabout as would be incurred at a stop sign, 5 seconds, and that the pedestrian stoplight is used somewhat frequently). Sure, the speed limit decrease only added 20 seconds to this route, but there are still much better routes to consider.

Improvement Option 1: Make Poplar Street two ways between Fourth Street and Broadway

Today, Poplar Street is one-way eastbound between Fourth Street and Broadway with what appears to be a single lane with two parking lanes on the sides. This option would simply take down a bunch of one-way signs, modify the stoplight at Broadway, and restripe this section of Poplar Street to be two lanes. This is probably the cheapest and lowest impact option that I will look at here, requiring no major construction or land acquisition. The older alternative that required traveling up to Spruce Street and doubling back on Broadway was 7.98 miles long; the new option is 7.80 miles long. The old route had two more stoplights than the new one. The old adjusted travel time was 13.97 minutes; the new route is 12.16 minutes (or 838 verse 730 seconds). While this would be a middle of the pack route, it still has major issues with having to deal with I-55 PSB traffic.

Improvement Option 2: Add a new, direct ramp from Westbound I-44 to Kingshighway

While I could probably give a couple long rants on how poorly MoDOT has handled I-44 access around Vandeventer, I will save them for later. The main purpose of this alternative is to improve reliability of the Kingshighway route by avoiding the railroad crossing found on McRee Avenue. For the distance calculations I will assume here that the entrance to Westbound I-44 from Vandeventer is removed for the new exit to Kingshighway, but in reality the Vandeventer entrance could remain by building a longer ramp to Kingshighway that either splits from I-44 before the bridge over Vandeventer and stays west of current entrance ramp (thus requiring more property), or by designing a new braided ramp to Kingshighway that arches over the current Vandeventer entrance.

Compared to the old Kingshighway option, the new option would be slightly longer (6.18 versus 6.06 miles). It would also have a slightly longer time to traverse compared to the older option (10.31 minutes versus 10.00 minutes, or 618 seconds versus 600 seconds). However, the 18 seconds could be much better than loosing 300 or more seconds due to a train, and the Kingshighway route would still be the fastest.

What about providing a grade separation for McReee Avenue over the UP track instead? While this would improve reliability for more travelers, there would be issues with providing property access that would increase the footprint of this alternative. In addition, the proximity of Vandeventer Avenue would require at least a six percent grade to obtain clearance without having to tinker with the Vandeventer/McRee intersection.

Improvement Option 3: Build an overpass carrying Spruce Street over the Depressed Section

This is the one option that may actually be under consideration by agencies in charge. In the original grand plan for the new I-70 river bridge, there was to be an overpass added for Spruce Street after the existing I-70 ramps to and from the Poplar were removed. However, due to the lack of funding that resulting the the defective new bridge plan being used today, and possible changes due to the Arch Grounds redevelopment, a new Spruce Street overpass may not happen at all.

The option here consists of building a simple two-way overpass that would still require removal of the I-70 PSB ramps, but would lessen the amount of doubling back required today by having to drive up Memorial all the way to Market Street before being able to head west across the Depressed Section. I will assume here that the new overpass has signalized intersections with both sides of Memorial Drive. This route would be 8.05 miles long, compared to the 8.48 miles from making a U-Turn on Memorial at Market or the 8.49 miles from heading west on Market to access Broadway. The adjusted time to traverse the new route would be 12.07 minutes, versus the 13.80 minute Memorial U-Turn route or the 14.32 minute Memorial and Market route. This would make this another middle of the travel time pack option.

Improvement Option 4: New Northbound I-55 to Westbound I-64 connector, Southside MTIA Plan

This one is based on a concept studied for the Southside Major Transportation Investment Analysis. It is barely visible in the map here:


This one was basically a new roadway starting from I-55 near the Park Avenue Exit and connector to I-64 at the Last Missouri Exit/Broadway Entrance, running near Sixth Street. For the purpose of this analysis, I've assumed the ramps would be posted at 45 miles per hour.

This option would provide an all-freeway route that would be around 7.49 miles long and take 8.20 minutes to traverse. However this route would still suffer from issues with I-55 PSB traffic, and community impacts make it unlikely to be built.

Improvement Option 5: New Northbound I-55 to Westbound I-64 ramp at the PSB

This option involves finding a way to add a new connector ramp in the interchange at the western end of the PSB. Given the proximity of the railroad viaducts, this would be difficult, and could require demolishing buildings along I-55 to add more space. The ramp would likely have a sharp curve and steep grade, so I've assumed a low speed for this ramp of 25 miles per hour. The ramp likely have to enter Westbound I-64 on the left side, and have design issues relating to the Eastbound I-64 lanes.

This route would be around 7.74 miles long and have a time to traverse of 8.64 minutes. While it would have less community impacts than the Southside MTIA ramp option, it easily makes up for those with its engineering difficulties.

Improvement Option 6: Complete MO 755 from I-55 to I-64

This option is probably the most unfeasible to be looked at here, due to impacts and prior opposition, but I'm including it for completeness. I've assumed MO 755 would generally follow the Truman Parkway to LaSalle Street, and then angle over to the I-64/22nd Street interchange. I've assumed MO 755 would have a 55 miles per hour speed limit, and the ramp to Westbound I-64 would be posted at 30 miles per hour.

This would be the fastest option with a time to traverse of 6.84 minutes, but would not quite be the shortest at 6.21 miles.

Conclusion

I've posted a chart comparing the improvement options to the top four existing routes (highlighted in a beige). Interestingly, the more infeasible the new option, the better it performs.



So should anything really be done? Yes; the Kingshighway interchange on I-44 should be fixed to include a direct connection to Kingshighway from Westbound I-44 that does not have the large railroad delays that drivers could face on the current route. But given MoDOT's prior investment in providing a full interchange at Vandeventer, this option is as unlikely to happen as one of those that provides for the movement without having to face a single stoplight.

Sunday, January 2, 2011

Predictions for the St. Louis area in 2011

I've decided to do a list of predictions for 2011 with three levels of confidence: High (or I'd be very surprised if it didn't happen, medium (could go either way; 50/50), and low (just for fun; I'd bet against them but am still guessing for the heck of it).

Note that most of these are being done on a combination of prior knowledge and gut feeling; I'm not reading any books or news articles as I type these.

High Confidence:

1) Gas prices will reach $4.09/gal for regular unleaded (87 Octane) on the Missouri side of the St. Louis area at this year.

2) A new multiple year transportation funding bill will not be passed in the U.S. Congress this year.

3) Left turn on red from a one-way street to another one-way street will remain illegal in Missouri.

4) No major movement on the Gateway Connector in Illinois. There may be some properties in the corridor being acquired, but the EIS process will not be started, nor will the project be completely dropped.

5) Illinois will not raise its speed limits on interstates to 70 miles per hour (this one is actually between medium and high confidence given the surprising attempt last year).

6) Major opposition will emerge to the South County Connector project.

Medium Confidence
1) Gas prices will reach $4.59/gal for regular unleaded on the Missouri side of the St. Louis area once this year.

2) Gas prices will stay above $4.00/gallon for regular unleaded for one month this year.

3) Red light and speed cameras will remain legal in Missouri (another one that would be in the high confidence group but I'm unsure how the Missouri legislature will act on it).

4) The new I-70 bridge across the Mississippi River will hit a snag that will either lead to costs increasing by at least $15 million or delay the project by at least six months. It may not necessarily be with the bridge, it could be with one of the contracts for the approaches, the Missouri Interchange, or the connections at the Tri-Level interchange in Illinois.

5) There will still be no word on which Metrolink expansion will be pursued next.

6) The Arch Grounds Redevelopment will proceed in the same method as planning for the I-70 Mississippi River Bridge: An expensive plan developed, available funding to achieve the plan will not be found, and the plan will be largely scaled back.

7) Major delays will occur on the Poplar Street Bridge due to more maintenance work.

8) The St. Louis area will have one too many red air quality days this year, and draw greater interest from the EPA.

9) The South County Connector will be shelved, with St. Louis County turning its attention to the Northwest Parkway or the River Valley Connector (or whatever the Chesterfield Valley to Maryland Heights route is being called now).

10) Definite, just awaiting funding plans will be well underway for the US 61 bypass of Hannibal, Missouri.

Low Confidence
1) A government agency in St. Charles County will provide funding to assist MoDOT with adding one or more interchanges to the US 61/Avenue of the Saints Corridor.

2) Plans for a new shopping center near the I-55 interchange will be announced in the latter half of the year, with serious work (not necessarily construction, but maybe planning and public meetings) for completing the interchange at I-55 and Weber Road.

3) Another Displaced Left Turn (like the MO 30 at Summit Road/Gravois Bluffs Boulevard intersection) or Median U-turn Intersection will be seriously considered somewhere on the Missouri side of the metro area.

4) A traffic calming project on a road in St. Louis City will trigger a large enough backlash that it is reversed (this includes anything from a four lane road being restriped to two lanes plus a center turn lane to a sidewalk extension at an intersection.

5) MoDOT will finally turn over Routes JJ and AB in St. Louis County to other agencies.

6) A project will start on I-70 in Missouri that will include evidence for the future truck only lanes.

Missing Movements 1: I-55 Northbound to I-64 Westbound: Part 1A

One minor update gained from recent travel in the area on Jefferson Avenue:

Regarding the stoplight at Jefferson Avenue and Chouteau: From the time the light turns red for Northbound Jefferson Avenue until the green left turn arrow for Northbound traffic comes up is about 52 seconds, so I would estimate at least a one minute delay incurred by missing this light. This adjustment would make change the adjusted time for this route from 12.11 minutes to 12.61 minutes. Still assuming the other stoplights are not coordinated, and still lacking data on most other signal timings, this would only drop the I-44/Jefferson route by one position - under the 12.25 minute Gravois/Tucker/Clark Avenue Entrance route.