The Real Problem of the Highway

And How To Get It Right
by Brendan Wittstruck


You probably woke up today to an Interregional Highway 35 choked with cars and caked in soot emissions, a resonant cacophony shaking the bones of passers-by.  Along its frontage roads, crumbling sidewalks callously underscore the apparent disdain in which the Texas Department of Transportation holds the people and homes who struggle to navigate its shadows.  And you’ll probably wake up to it tomorrow.

IH35 can have a better future if the will exists to design it for the use of the people of Austin rather than the cars of Austin.  The real problem of IH35 through central Austin lies not in its throughput capacity but in how it cuts off east-west movement and how its frontage roads antagonize the movements of the city by failing in every measure to be local streets.  Put another way, the problem of the highway isn’t the highway at all: it’s how it connects, or doesn’t, to the city through which it runs.  Above all else, this means improving crossings to promote pedestrian and cyclist participation and comfort and clearly establishing frontage roads as local streets. 

In June of 2015, Senator Kirk Watson’s office announced a plan for a $4.3 billion overhaul for IH35 between Georgetown and San Marcos.[1]  This sort of talk may ring a bell for those of you with long memories, given that IH35 improvement plans first surfaced in 1987.[2]  Though potentially stymied by recent legislative action rejecting greater use of public-private partnerships for road construction, portions of the plans, dubbed Mobility35, are already in various stages of design and construction.[3]

For Austinites, the Mobility35 Plans are flawed in several measures.  For one thing, they are entirely predicated upon the belief that new lanes will translate to improved traffic flow; however, the concept of traffic generation (simply, that more capacity generates more use) suggests that traffic volume will actually escalate in response to newfound capacity.  The evidence of this has been on spectacular display regionally as the bloated 26-lane Katy Freeway (I-10) in West Houston has seen congestion levels spike, rather than drop, after its enlargement.[4]  There are myriad other concerns with the plans, which continue their slow but inexorable march over the city and without meaningful engagement of City leadership and staff.

But my argument here is in support the “other life” of the highway, the ecosystem of people living and moving around it, which is yet another measure in which the current plans fail wantonly.  The problem in this regard is clear: TxDOT measures the performance of its highway projects through a single metric, Level of Service, which is best described as a measure of travel time for vehicles.  This myopic focus on capacity is responsible for IH35’s greatest shortcoming: its near stranglehold on the movements and access of Central Austin.  Simply put, IH35 has disconnected us, literally and figuratively, since its construction and still does today.  Instead of Level of Service we should be measuring the merits of IH35 plans through Level of Access.

Intersections: The Importance of Connectivity
Access is the most sympathetic measurement of mobility success within an urban environment; measuring access means making design decisions to improve fluidity of movement, ease of connections, comfort and safety for pedestrians, utility for residential neighborhoods, support of all modes of travel and attending to the needs of users of all ages and abilities.  Central to this is connectivity—simply, that places connect to each other and can be reasonably accessed by all people.   That connectivity is such a driver for equity in access explains why it is so baked into the core values of the City’s Imagine Austin Comprehensive Plan.

Connectivity, though, is systematically hindered through the downtown area by IH35, especially when compared to other significant parallel streets.  From Cesar Chavez Street to 11th Street in front of the State Capitol, for example, Congress Avenue functionally sees seven total crossings (counting pairs of one-way streets as a single crossing) it its approximately one-mile run.[5]  Over its parallel run in the same distance, IH35 has only three—less than half the total level of connectivity of Congress Avenue.  Even Waller Creek and Shoal Creek—legitimate natural barriers—each boast more crossing points than IH35 through downtown.

IH35 connectivity gets even worse outside of downtown, where its run through north central first- and second-ring subdivisions sees a total of only five crossings over nearly three and a half miles.  Neighborhood subdivisions built prior to IH35 have seen their connections across it severed; ones built in the mid-Century were never even connected in the first place.  Indeed, the farther north you travel along IH35, the more obvious its impact becomes on the stratification of central and north Austin neighborhoods.

This is important because the lack of crossings at IH35 through downtown means that all pedestrians, transit users, bicyclists and motorists wishing to cross the interstate corridor are funneled into a very small number of paths to do so, encumbering these intersections with disproportionate traffic loads compared to the rest of the street grid.  Having a network of streets doesn’t do us much good when we’re only electing to use a handful of those streets.

Existing/Mobility35 proposed IH35 Crossings
image by the author using google maps

Unfortunately, the current Mobility35 plans do not actually add any new crossings between 290 and Lady Bird Lake.  There are a number of potential solutions to this problem but the most modest one is to re-evaluate what TxDOT refers to as the “Lowered” option to emphasize creating new connections rather than merely maintaining the existing ones.  This would require a selective re-engineering or removal of some on- and off-ramps through downtown and would double the downtown connectivity by re-opening 3rd, 4th, 5th and 15th Streets across IH35.  There are clear multimodal benefits to this, including the enhanced crossings of the MetroRail red line and the Armstrong bikeway.

Adding crossings downtown pales to the mobility and community value that would come of lowering the main lanes all the way to 290 and increasing connectivity in north central Austin.  In this vision, residents in Cherrywood and Hancock, whose streets once met at the former East Avenue (now IH35), would see their east-west access more than triple with the re-introduction of direct connections at 30th, 32nd, Luther/Edgewood and Concordia Streets.  Farther north, neighborhood subdivisions that never connected in the first place would for the first time be able to enjoy potential connections such as 45th/Fernwood, 46th/Bentwood, 49th/Barbara Jordan, 52nd and 53rd Streets.  In total, a connected vision of IH35 through north central and downtown Austin could realize fifteen or more new connections, each of which would relieve congestion pressure on the few existing, overburdened interchanges.

potential expanded crossings with lowered ih35
image by the author using google maps

Frontage Roads: The Highway Next to the Highway
Where the connections across IH35 are key toward the unified, resilient local road network that is needed to ameliorate the city’s access woes, the design of the frontage roads is the key indicator of how the highway’s edges will either support or detract from the quality of life of those living, working and moving along the corridor.

Downtown Austin’s frontage roads are mostly unique for a major Texas city in that they function in the manner of exurban and rural access roads rather than as part of an urban street grid.  When urban interstates were imposed in the mid Century upon more established Texas cities, including Dallas, Houston and San Antonio, the level of complexity of their introduction into city centers meant that they usually worked in constrained environments and frontage roads behaved more similarly to non-interstate local streets.  Austin, a gangling adolescent in the mid Century, lacked many of these constraints, evident today in oversized, vehicle-centric frontage.  In Austin, the frontage roads are a highway next to a highway.

The effect of this is as predictable as it is tragic.  Through central Austin, IH35’s frontage roads have posted speeds between forty and forty five miles per hour.  Statistics show that a pedestrian struck by a motorist at forty miles per hour has only one  chance in ten of survival; in the same circumstance at thirty miles per hour, that survival chance jumps to fifty percent.[6]  Sadly, a visualization of traffic fatalities in Austin makes the line of IH35 painfully visible.[7] 

This does not even account for the pedestrians not injured because they were never there in the first place.  IH35’s frontage roads are an accessibility embarrassment for the city.  Incomplete sidewalks or sidewalks hopefully in need of repair prevent equitable access along the corridor.  The street tree coverage that defines the City’s Great Streets program and Subchapter E standards for urban roadways is considered a hazard to motorists (rather than protection for pedestrians).

existing frontage road accessibility and city of austin great streets section
image credits (Left to right): author, City of Austin great streets development program

In total, this paints a bleak picture of the level of attractiveness of IH35’s frontage roads to users on foot, bike or wheelchair.  This, in turn, inhibits local business development and creates empty, unsafe places.  The natural aversion of people to this environment further contributes to the division of neighborhoods and itself contributes to additional vehicle miles traveled in situations where many people could walk or bike if they did not fear for their lives in doing so.  Most importantly, its inhospitable nature is a violation of the inalienable rights of people to move freely and safely.

A vision for IH35 needs to embrace the frontage roads not as auxiliaries to the interstate but as local roads in their own right.  Fortunately, Austin has strong existing standards for precisely how to do this and they should be applied to the city’s largest corridor.  This vision should explore policy decisions, included posted and design speeds, as well as design decisions, including the limiting of free right turns, the narrowing of curb radii and the introduction and maintenance of protected bicycle lanes, shaded pedestrian refuge areas, street trees, green infrastructure and pedestrian-scaled signs and lighting.

Conclusion: It Could Be Worse But It Must Be Better
Austin has come close to doing disastrous things in defense against the reality and perception of its connectivity problems in the past.  The Austin Transportation Plan, 1962-1982, the local apotheosis of mid-Century urban renewal planning, offers a terrifying glimpse of how the planning logic of the time would have had Austin look today:

Austin planned arterial network, 1962-1982
source: austin transportation plan, 1962-1982; image courtesy of

Our contemporary understanding of mobility recognizes that nearly the entirety of downtown traffic congestion issues arises from choke points, including IH35, Lady Bird Lake and the Guadalupe Street jog at Martin Luther King Jr. Boulevard, which subvert the natural fluidity and resilience of a grid system by channeling it into a handful of overburdened intersections.  Imagine if the 1962-82 Plan—which called for the addition of the Town Lake Expressway along West Cesar Chavez and East Riverside, a grid-busting Crosstown Expressway through the Clarksville and Chestnut neighborhoods and the Central Expressway, which would have obliterated the Drag—had been realized in its entirely.  It could have been much, much worse.

But it needs to be better.

Better starts with a vision.  Realistically, lowering IH35 through 290 is a proposal that would require vastly—nearly impossibly—more coordination, planning, funding and vision than the Mobility35 plans, largely because it is predicated on the complete removal of the upper decks.  The expense of lowering the main lanes, not to mention construction time and impact, would also be far greater than that of downtown, owing to the longer distance and less potential return on investment where funding mechanisms like Tax Increment Financing zones or Public Improvement Districts are not economically viable in the foreseeable future.  But I challenge that any investment in IH35 absolutely must be undertaken with vigor for a vision of a hopeful future instead of a retreat into doing little for the sake of doing.  We will not see IH35 become a better neighbor if we do not dream it first.

Better means that access, rather than throughput, must be the metric of success.  An IH35 measured only through Level of Service is one that is diametrically opposed to that measured through Level of Access.  The latter we celebrate in the ability of all people, of all abilities and through all modes of travel to get from place to place; the former is calculated only in the speed of cars and the capacity of the road to enable them.  Level of Service doesn’t just inhibit Level of Access; it kills it.

This is why the “other life” of IH35 is the conversation we should be having when we talk about the interstate.  A vision of IH35 that connects communities, fosters small and large businesses, enables users of all modes and abilities and values the lives, comfort and safety of its neighbors over saving commuters a few seconds on travel time Is a vision that encourages the health and well-being of the residents, visitors and businesses of Austin.  The good news is that we have the design and policy standards to achieve this.  There is a future for IH35 that is more connected and more welcoming, and when we demand this future we will get the highway right.


This essay was originally published in Austin Towers Blog here


[1] Denney, Amy. “TxDOT seeks funding for $4.3 billion plan on I-35”. Community Impact. <>.

[2] Clark-Madison, Mike. “Taking the Slow Road”. Austin Chronicle. <>.

[3] Shelton, Kyle. “Tapping the brakes on public-private partnerships in Texas”. Brookings Institute. <>

[4] Cortright, Joe. “Reducing Congestion: Katy Didn’t”. City Observatory. <>.

[5] This does not account for the recent two-way conversion of Fifth Street; this and projects like it will could nearly double the total number of functional crossings at Congress Avenue.

[6] Schmitt, Angie. “Cities Want to Save Lives with Lower Speed Limits, but States Stand in the Way”. StreetsBlogUSA. <>.

[7] Vision Zero ATX, Austin Fatality Map 2015. <>.