The new I-70 river bridge: Not the best project that could be

The new Mississippi River bridge currently being built north of downtown St. Louis is supposed to relieve congestion on the PSB. However, for many reasons, it may have not been the best project that could have been pursued. Consider:

* Westbound I-70 traffic already has a non-stop alternative to the PSB via the MLK Bridge. Eastbound I-70 traffic only has to face one light before entering the MLK Bridge. Using the MLK Bridge for through movements to WB I-44 or SB I-55 requires a long trip through downtown to return to the interstate. EB I-44 or NB I-55 through movements have a slightly easier time accessing the MLK - except when special events close Memorial Drive - but it still requires a mile long drive through downtown. This route also includes a sometimes difficult right turn onto Convention Plaza to access the MLK Bridge.

* The I-55 PSB ramps seem to back up regularly outside of rush hour, while the I-70 ramps are almost always free flowing outside of rush hour, excluding ball games.

* Sure, MoDOT says they will fix the access issues if a companion bridge is built in the future. However, there is no guarantee that the companion bridge will ever be built. In addition, what happens should the PSB become unusable for a long period due to a barge collision, severe hazmat accident, or increasing maintenance issues?

Driving Distances
For traffic heading to I-70 or I-55 beyond Troy:

• From the I-70/I-270 interchange:

- 30.8 miles via I-270
- 38.9 miles via the PSB
- 37.23 via the new bridge (initial build)

• From the I-55/I-270/I-255 interchange:

- 34.7 miles via I-255
- 32.7 miles via the PSB
- 34.3 miles via the new bridge had access been provided in the initial phase

• From the I-44/I-270 interchange:

- 40.5 miles via I-270 and I-255
- 35.4 miles via the PSB
- 45.1 miles via I-270
- 37.0 miles via the new bridge had access been provided in the initial phase

For traffic heading to I-64 east of St. Louis, using the point where the I-255 ramps merge onto I-64 as the eastern end:

• From I-44 at I-270:

- 26.5 miles via I-270 and I-255
- 23.2 miles via the PSB
- 24.66 via the new bridge had access been provided in the initial phase

• From I-55 at the I-255/I-270 interchange:

- 20.6 miles via I-255
- 21.9 miles via the PSB
- 23.36 miles via the new bridge had access been provided in the initial phase

• From the I-70/I-64/US 61 interchange at Wentzville:

- 48.2 miles via I-64 and the PSB
- 47.2 miles via I-70 and the PSB
- 58.5 miles via I-64, I-270 south, and I-255
- 56.3 miles via I-70, I-270 east, and I-255
- 52.7 miles via I-70, I-170, I-64 and the PSB
- 45.45 miles via I-70 and the new bridge

What Could Be Done
Since it is too late now to abort the project and instead look again at a new bridge south of the PSB, there are a couple of changes to the new bridge project that could make this project much more useful to all.

* Add a new WB I-70 exit and a new EB I-70 entrance between Memorial Drive and the new bridge. While not an ideal solution, this would at least make it easier to access the new bridge from the south without as much time sitting at stoplights. The best location would be at Cass Avenue, but new ramps here would require closing the existing EB exit/WB entrance to/from Broadway or using a more costly braided design.

* Replace the current entrance to WB I-70 south of St. Louis Avenue with a new WB exit. This would at least allow a somewhat indirect U-turn option that might aid in any closure of the PSB

* Simply add the ramps to the south. Supposedly adding those ramps now would be incompatible with a future companion span, but the current design is not entirely compatible with the companion either. The connection between EB I-70 and the first bridge will be unneeded and require modification and removal, so why not modify it in the initial build to allow a more useful product?

New lanes opening on I-55 in Jefferson County

By this time I-55 between Route M and Route Z - or just north of the bridge over the BNSF track just north of Route Z for northbound traffic - in Jefferson County should be six lanes wide.

Link to MoDOT press release

This much needed improvement is only a start; there are still 16 miles that need at least one more lane each way between Route Z and the cloverleaf with US 67.

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.

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

This could be a recurring series where I have fun with a spreadsheet and online satellite imagery to try and determine the best route between two points which is hindered by a canceled highway project.

The cancellation of MO 755 took with the best plan to provide connections between I-55 and I-64 (another option, via a freeway in the Kingshighway corridor, died even earlier). Today, using a spreadsheet for calculations and measuring distances via online satellite images, I will attempt to estimate the best way to make the move between Northbound I-55 and Westbound I-64. Due to differences in ramp configurations, turn prohibitions, and one-way streets, the result may not be the same for the Eastbound I-64 to Southbound I-55 movement.

A few assumptions for these calculations:

1) Travel speed was set at the posted speed limit, or posted ramp advisory speed. If the speed limit for a route was unknown, it was guessed.

2) All stop signs encountered add five seconds to the travel time (I’m just guessing on this value). Having to wait for other vehicles to take their turn would add more time, but since such additions are random, I will stick with the five second addition.

3) All intersections with a traffic signal will add 30 seconds to a route. Yes, on some days many traffic lights will be encountered in the green phase and not add any time, while some traffic lights will likely add more than a minute. Since this is an informal project for fun, I don’t feel like taking the time and hassle to obtain signal timing information from MoDOT and St. Louis City.

4) If a yield sign is encountered for a right turn next to a stop sign, no time is added. For a yield sign next to a traffic light, 30 seconds will be added. This is another subjective choice, but if one gets to the yield sign at the same time the adjacent stoplight changes, it can take just as long as if the turn was also controlled by the stoplight.

5) All speed changes are instantaneous.

6) No time penalties for turns – I may fix this in a future version.

7) No delays from traffic congestion
Measurements were started from the Sidney Street Bridge over I-55 and ended at the Tamm Avenue Bridge over I-64.

The routes evaluated, going from east to west:

1) Stay on I-55 into Illinois and make a U-Turn using the ramp between the Tudor Exit and Piggott Entrance

This is the longest and most indirect route evaluated at 11.24 miles (59,363’) but the only all-freeway option available. Travel time via this route is 12.9 minutes (778 seconds).

On many days, the travel time value will be greater due to having to face PSB congestion twice. Northbound traffic can back up to the I-44 merge on the worst days, while traffic for Southbound I-55 can back up over the PSB and congested the adjacent lanes, or even make accessing Westbound I-64 from the westbound Collector-Distributor (C-D) roadway near impossible.

2) Exit at Memorial Drive, make a U-Turn at Market Street, travel south to Spruce Street, take Spruce Street west to Broadway, and access Westbound I-64 from Broadway.

This is one of the longer routes both for distance (8.48 miles) and travel time. Encountering eight stoplights, this route would take around 13.8 minutes to traverse.

Like the Tudor U-Turn route, this route is also susceptible to PSB congestion, although Southbound Memorial Drive does not seem to back up as much as the I-55 ramps to and from the PSB. This route is more susceptible to congestion from Busch Stadium, and is completely unusable whenever Memorial Drive is closed. The traffic lights at Market also takes a long time to cycle through, which may add an additional minute to this route.

3) Exit at Memorial Drive, take Market Street west to Broadway, and then head south on Broadway to access I-64.

This route is similar in length (8.49 miles) to simply making a U-Turn on Memorial, but an additional stoplight can add additional time to this route, making it take 14.32 minutes to traverse.

4) Exit I-55 at Park Avenue, take Fourth Street north to Clark Avenue, take Clark Avenue to Broadway, and then take Broadway back south to access I-64

This route, 7.98 miles long, faces nine stoplights, giving it a travel time of 13.97 minutes. However, congestion from the Northbound I-55 ramp to the PSB can make accessing this route impossible.

5) Exit I-55 at Park Avenue, take Seventh Street north to Clark Avenue, take Clark east to Broadway, and then head south on Broadway to access I-64

This route is less direct than taking Fourth Street to Clark. At 8.13 miles long and with 11 stoplights, this route takes 15.28 minutes to traverse.

6) Exit I-55 at Park Avenue, take Seventh Street north to Clark Avenue, take Clark west to the 10th Street entrance to I-64

While shorter than the other routes using the Park Avenue Exit at 7.73 miles, the 10 stoplights along this route could make this route take at least 14.18 minutes to traverse (assuming all green lights, the time could be as little as 9.19 minutes).

7) Exit I-55 at Gravois Avenue, take the Gravois/Tucker corridor to Clark Avenue, then head east on Clark Avenue to access the 10th Street Entrance to I-64

One would encounter nine stoplights on this 7.45 mile route, given it a time to traverse of 13.70 minutes (or as little as 9.20 on all green lights).

8) Exit I-55 at Gravois Avenue, take the Gravois/Tucker corridor to Clark Avenue, then head west to access I-64 from Clark Avenue

This one has a length of 7.10 miles, encounters seven stoplights, and has a time to traverse of 12.25 minutes

9) Take the Truman Parkway north to Chouteau, head east on Chouteau to 14th Street, then north on 14th to the entrance ramp to I-64 at the Clark Avenue intersection

This 7.10 mile route encounters six stoplights and one stop sign and requires around 11.82 minutes to traverse.

10) Take the Truman Parkway north to Chouteau, head west on Chouteau to Jefferson, then north on Jefferson to I-64

This route is 6.49 miles long and has seven stoplights. Time to traverse this option is 11.69 minutes.

11) Take I-44 west to Jefferson, then north on Jefferson to I-64

Depending upon traffic, this route may not be possible since there is a little short of a half mile to weave across I-44 to access the Jefferson Avenue exit. This route is 6.55 miles long, has eight stoplights and takes around 12.11 minutes to traverse (or 8.11 minutes on all green lights, but at least for me that used to be pretty hard to get).

Even though the ramp to Westbound I-44 from Northbound I-55 is posted for 20 miles per hour, many drivers seem to ignore that posting, so for this exercise the speed of the ramp was taken as 30 miles per hour (using 20 miles per hour increase the travel time by about five seconds). All further routes keep the 30 miles per hour speed for this ramp.

12) Take I-44 west to the Grand Avenue Exit, take Lafayette Avenue west to Compton Avenue, take Compton north to Market Street, then head west on Market to access I-64.

This route encounters the most stop signs of any route analyzed here (four), but the second least amount of traffic lights (three). It has the second shortest estimated travel time at 10.74 minutes (with no stop signs or traffic lights it would take 8.91 minutes to traverse). The route is 6.92 miles long.

13) Take I-44 west to the Grand Avenue Exit, take Lafayette Avenue to Grand, then take Grand north to I-64

This route has one stop sign and six stoplights. In addition, the left turn to access Westbound I-64 may be unsignalized, but the large volume of opposing traffic can add some more delay. I also have some doubts regarding congestion on this route; the nearby interchange with Forest Park Avenue seems prone to backing up traffic on Grand.

This route is 6.62 miles long and has an estimated time to traverse of 11.35 minutes.

14) Take I-44 west to the Vandeventer/Kingshighway Exit, take McRee Avenue west to Kingshighway, then proceed north on Kingshighway to I-64

Using the chosen parameters for stoplight delay, this is the quickest route at 10.15 minutes. However, since there does not seem to be a posted speed limit on McRee Avenue, the speed limit for this street was assumed to be the St. Louis City standard of 25 miles per hour, even though I recall a higher speed limit being posted in the past. This route is also the shortest route distance wise at 6.06 miles. This route has six stop lights, but I recall the light at Chouteau to be fairly long. In addition, this is the only route which involves an at-grade railroad crossing. Although this track is lightly used, one risks a long (maybe greater than five minutes) delay with this route.

15) Take I-44 west to Hampton, then take Hampton Avenue north to I-64.

This route has the second shortest distance at 6.24 miles. It has the third lowest time to traverse at 11.31 minutes (but if one gets all green lights, it has the shortest time to traverse at 7.3 minutes). There are eight stoplights on this route.

During the past year, as can be seen on Google’s satellite images of the area, Hampton experienced congestion from traffic accessing Forest Park. This could be a potential deal breaker for this route.

Conclusion

I've summarized the data into the following table. Base Time is how long the route would take without any stoplights or stop signs, while Adjusted Time 1 is how long the route would take assuming each stop sign adds 5 seconds and each stoplight adds 30 seconds.



(Edit 1-11-2011: Fixed the chart to correctly show the number of stop signs)

Now if someone absolutely had to have a route recommended to them, I would unfortunately have to recommend the I-44/Compton/Market option since it appears to be more reliable than either the Kingshighway or Hampton options. Can't say I'm thrilled with recommending this residential route, although East-West Gateway does show Compton classified as a minor artierial between Gravois and Martin Luther King Drive (see http://www.ewgateway.org/pdffiles/library/trans/funcclassapp/fc-StlCity.pdf). Remove the railroad crossing from McRee Avenue and I would happily recommend using Kingshighway. Guarantee that Hampton would not turn into a parking lot again on the next 70 degree day, and I would recommend that route.

In part 2, I will take a look at possible alternatives for further reducing travel times and improving reliability on some of the routes between Northbound I-55 and Westbound I-64.

Sign work on I-55

Two minor sign related items to post about:

1) The speed limit sign on Southbound I-55 just south of Butler Hill Road has been changed back to one reading 65 mph.

2) MoDOT has been working on two of the overhead signs on the elevated section of NB I-55 between the PSB and I-44 for the last two evenings in a row.

April 9th Groundbreaking for New I-55 Lanes in Jefferson County

On April 9th, MoDOT will hold an official groundbreaking for adding one lane each way in the median of I-55 between Route M and Route Z.

Given the large amount of traffic that uses this route, even in the off-peak hours, this is a much needed improvement. Due to funding concerns, the extra lanes will not be going as far as ultimately planned - I-55 is supposed to stay four lanes each way down to the Herculaneum Exit.

Various MoDOT Project Updates #1

* MoDOT will break ground on the MO 141 expansion/relocation between St. Luke's Hospital Road and MO 340/Olive Boulevard on March 15.

* On the same day, MoDOT will close the NB I-55 exit to Route M in Jefferson County as part of the widening project on I-55 between Route M and Route Z. While the official detour uses US 61-67 to the east, the west outer road (Metropolitan Boulevard) may be just as convenient.

* Lane closures begin today for the repaving and widening of I-44 between the Pacific Exit and the Washington Exit (the western MO 100 interchange). Since this project will have the usual narrow lanes crammed between jersey barrier driving, MO 30 may be a less stressful alternative. for through traffic. Alternatively, Business Loop 44/Old US 66 may be nicer for traffic that needs to stay close to the I-44 corridor near Pacific.