Should the light at the end of this tunnel be a green one?

Interview published by Dowtown Houston Guide.

Houstonians are no strangers to traffic; it is the price we pay for growth. However at times we wonder if the “one size fits all” solutions really evaluate the differences inherent from one city to another. For a city that pushes growth forward both inward and outward, the talk of construction on yet another roadway may make even the most die-hard commuters anti-growth. The folks at TxDOT have their sights on I45 between Downtown\Highway 59 and the Woodlands as Houston’s next major roadway project. Many Houstonians have their qualms with TxDOT as plans and projects appear to remain in a vacuum until the day of construction. For many the re-design of the I10 corridor left little in the way of transit alternatives, and generated a costly and lengthy process of condemning prime real estate. As it stands now the boiler-plate plan that TxDOT is proposing to implement in Houston calls for doubling the width of I45 by adding shoulders and managed lanes. Commuters will encounter closed and converged roadways during the duration of this construction as is typical with projects of these sorts. To say that one might resolve the fate of their commute to TxDOT’s blueprint rooms would be a rational idea, if not for the fact that a proposed alternative exists. Ironically TxDOT's Dallas District is actually proposing a 2.5-mile tunnel in north Dallas, yet such a proposal for Houston was not de rigueur. Irregardless of what occurs in Dallas, a group of Houstonians has sought to bring a tunnel concept to Houston’s roadways and have heralding its benefits to the Houston area.

Research and inquires into the alternate proposal found its design and solutions to be a very formidable alternative. The author is seeking a feasibility study to examine the details necessary for construction. I contacted the plan’s author Gonzalo Camacho, of Camacho & Associates to answer questions that many commuters and residents might have about TxDOT’s plans and his proposed alternative.

DH: What is your background both as a Houstonian and transportation engineer?

GC: I received my B.S. in Civil Engineering and M.S. in transportation engineering at the University of Texas at Arlington and have practiced transportation/traffic engineering for over 12 years, mostly in Houston except a short time period while working on the Dallas light rail program.

DH: The proposal as I understand calls for routing traffic under the existing roadway by means of a tunnel. Would the construction of the proposed tunnel close sections of I45, or would these tunnels be constructed under the live roadway?

GC: The reason why we are asking to do the feasibility study is to determine some of these details. However, most of the construction will be conducted below ground. Surface construction will occur where construction needs access to the tunnel, normally at the beginning or end of the tunnel. Where most of the disturbance of existing traffic will occur is when connecting the roadway tunnels to existing highway lanes. Potential locations may include direct connectors at Beltway 8, Loop 610, I-10 and US-59 but this is assuming that TxDOT will tunnel the 15 miles connecting Beltway 8 to US-59.

DH: Your proposal calls for minimal impact on the existing I45 roadway during tunnel construction. How is this possible?

GC: There will be some impact when existing lanes will be connected to the tunnels but these will certainly not take 5 to 10 years. Access locations for building the tunnels does not need to be over the existing I-45, but can be done outside the area of traffic impact. Again, some of these details have to be considered but we will not have appropriate answers unless a feasibility study is done.

DH: What would be the state of the current I45 roadway after tunnel completion, would it be retained or would its function be changed?

GC: There are several options. The most economical would be to leave I-45 as it is but reconfigure the number of lanes through pavement markings. This would standardize the width for shoulders, include additional HOV lane, and reduce number of through lanes so it serves local traffic. The other option is to phase out segments of I-45 so that local traffic gets an express street similar in concept to Allen Parkway. The transit option is to take the center portion of I-45 and turn it into a mass transit corridor and eventually develop an express boulevard instead of the at-grade highway. This is based on the concept that most through traffic will take the tunnel and local traffic will take the express boulevard.

DH: You mentioned expansion of the HOV lane, what would be the status of the HOV lane after the tunnel completion and how does it fit into your plan?

GC: The simplest option is to reconfigure the existing lanes on I-45 to add the two HOV lanes that METRO has identified on the MIS (major investment study). Or these could be incorporated inside the tunnel thus allowing for more capacity on the existing at-grade I-45. The future of transit on the I-45 is a key factor on the tunnel concept, thus it is so important for METRO to be part of the decision making process.

DH: If the primary problem is limited capacity of the current roadway and little room to widen, why would a removal of the current roadway be advisable post tunnel completion? In other words, why not simply add the tunnels under the current infrastructure permanently?

GC: TxDOT is probably more qualified to determine if the "primary problem is limited capacity." My understanding is that TxDOT does not plan to purchase significant right-of-way for the purpose to add more capacity but TxDOT has the need to rebuild I-45 mainly because it is an old infrastructure and design standards need to be updated - current facility has narrow shoulders and short on/off merging distances.

I would advise the reconfiguration of the at-grade highway for something similar to Allen Parkway for several reasons: enhance the quality of life and business along the I-45 corridor, reduce the negative effects of I-45 on the environment and people's health, enhance redevelopment of the corridor with transit, and provide an express corridor for through traffic or traffic accessing the airport to downtown. On the other hand the tunnels could be added to the current I-45 but this will not exclude the fact that I-45 needs to be reconstructed and under current operating conditions it is "unsafe."

DH: How is the capacity of transit calculated for a project such as this? Are the estimates forward looking enough to address future growth?

GC: Metro is best qualified to answer this. To my understanding Metro has current models that allow estimation of transit trips. However, I think the key element to the tunnel system in conjunction with mass transit is the option that I-45 drivers could have by parking their vehicles at Greenspoint and ride Metro into town (save time, gas, stress, etc). Transit trips can be made move attractive by regulating the cost of toll in the tunnel, cost of parking in downtown, and congestion of traffic at local streets. Take in consideration the inconvenience that has become driving to the Medical Center - many people going to the Medical Center might choose to drive out of their way to access the park and ride facility at Greenspoint

DH: Houstonians are already familiar with the Washburn and Baytown tunnels as examples of past tunnel projects in our area. How does this proposal compare in terms of distance, capacity, and engineering.

GC: Regarding distances: I believe these tunnels were/is shorter than one mile. The Beltway 8 to US-59 is about 14.5 miles.

On the capacity: If not mistaken the purpose of the Washburn and Baytown tunnels were to cross under the bay, probably to avoid building a very high bridge. Also these tunnels served smaller communities and not a city with over two million people. The interesting consideration for building a tunnel across a bay vs. a bridge is the potential for a barge to run into the bridge piers, which has happened several times along the Gulf Coast in the last few years. Also, in case of a hurricane perhaps a tunnel is a safer way to evacuate the coast.

DH: Building a tunnel sounds inherently expensive. How does this project compare to the alternatives utilizing the following metrics: Construction costs, condemnation/annexing of private land, lost productivity relative to congestion, specific requirements/infrastructure to maintain tunnel roadways.

GC: Dr. Sauer, the gentleman from Austria who is an international expert in tunneling and has been instrumental in helping me investigate the feasibility of building I-45 in tunnels has put together a presentation for METRO. In this presentation he outlines the related costs for building various types of roadways, at-grade, elevated, depressed and tunnels. The following is the copy of the exhibit that shows some costs of various types of construction.

However, this does not identify costs related to: construction congestion lost of businesses due to construction, potential to generate revenue via user fees, long term operation and maintenance costs, environmental benefits, quality of life benefits, and more importantly the vision that this type of project could offer Houston in the eyes of the world. One interesting area that should be investigated is the long term cost for operating, maintaining and replacing a traditional highway vs. a roadway tunnels. Another area that MUST be investigated is the health and environmental benefits of tunneling a highway. Some of these analyses are not commonly done.

DH: How does a tunnel fare in terms of safety as compared to other roadway methods? Specifically, how would a multi-car accident resulting in a fire effect the safety of other drivers

GC: This is out of my area of expertise but I can share with you findings of my investigation on safety. Tunneling is not a new concept and it is very common in European countries and Japan. Tunnels are being constructed in Malaysia and Australia. Therefore safety issues/concerns have or should been addressed by all of the entities in charge of managing and operating roadway tunnels. Multi car accidents are probably not much different on an open road vs. a tunnel except the element of constrained space. I would think tunnels are safer than open on/off highways so, it would reduce the potential for crashes. Because of limited access traffic in tunnels can be managed more efficiently. The ability to control the flow of air/ventilation allows to take air away from fires and divert smoke away from people, i.e. divert smoke and toxic fumes towards the front of the crash where most traffic is cleared and away from behind where most traffic normally backs up. Many tunnels are provided with sprinkler systems as well as cameras. In addition tunnels provide for escape routes and alternative safety access (a smaller tunnel that parallels and connect to the main tunnels). The federal government has conducted studies on safety of roadway in particular for bridges and tunnels. Therefore, safety has been addressed at many levels.

DH: For those that may have arrived in the past hour, Houston is built on a variety of soil types and has a flat topography. How do tunnels deal with water or flooding?

GC: To my understanding the more homogeneous the soil conditions are the best for building tunnels even if the water table is high. Per Dr. Sauer coupled with a local geotech expert who was consulted on the soil and geological conditions of the I-45 corridor have indicated that Houston soil conditions are favorable for tunneling. One interesting item was discovered by Dr. Sauer during a trip to Spain while investigating new technologies and current tunneling projects. The following image is from Dr. Sauer's presentation for METRO. It shows a roadway tunnel currently being built in Malaysia. It incorporates a running stream at the base of the tunnel and the tunnel is design in such a way that will allow flooding of the tunnel to prevent up-stream flooding during the monsoon season - traffic will be stopped and water allowed to drain through the tunnel, once the flooding is over the tunnels will be washed and open to traffic.

DH: While on the subject of Houston’s environment, how do tunnels make the air cleaner?

GC: Many tunnels I have investigated use electro static precipitation to filter air from the tunnel before it is sent outside. Because of pollution from cars, tunnels are required to include air circulation systems. Air purification is incorporated into the air circulation systems. Depending on the air velocity up to 90 % of suspended solids can be removed. Therefore, to my knowledge, roadway tunnels are the only transportation type roadway alternative that allows air filtration.

DH: This aspect impresses me most. For once the relative pollution count of a section of Houston is not dependant on wind, rain, or congestion. I would also hazard a guess that the lower radiant heat load a tunnel contains would do wonders for a summer commute and further reduce drivers stress.

Mr. Camacho, I would like to thank you for your time and participation and I hope that your plan receives the feasibility study that it deserves.

For more information visit www.i45parkway.com