How urban rail can be installed in the Guadalupe-Lamar corridor10 October 2013
by Lyndon Henry
Some supporters of the Guadalupe-Lamar (G-L) corridor for Austin’s urban rail starter line have been seeking details about how urban rail (i.e., light rail transit, or LRT) would be installed in these thoroughfares — running in mixed traffic, in reserved lanes, or how? At about the same time, proponents of the Official (aka City of Austin-Capital Metro) proposal for an urban rail line from downtown to Mueller have recently begun raising the issue of right-of-way (ROW) constraints in this same G-L corridor.
It’s important to keep in mind that the Mueller proposal itself has its own ROW constraints and other challenges, but I think it would be helpful here to address some of the issues in the G-L corridor. One of the reasons for this is that I’m not convinced that all parties in the Project Connect team will necessarily make a good-faith effort to find a truly workable, affordable design for inserting urban rail into the G-L thoroughfare alignments — and advocates need to be prepared to insist that valid (and proven) alternatives be examined.
The basic idea is for urban rail (light rail transit, LRT) to operate totally, or almost entirely, in its own lanes. This would require some reconstruction of Lamar Blvd. and probably Guadalupe St. in sections, including slight narrowing of existing lanes, elimination of the turning (“chicken”) lane and replacement with transit-integrated traffic controls (such as left turn lanes), and other measures. Light rail systems in places like Portland, Dallas, Houston, Phoenix, Denver, Salt Lake City, etc. are models for this.
Also keep in mind that Project Connect’s longer-range plan for buses on Lamar-Guadalupe is to install tens of millions of dollars’ worth of reserved lanes — so official planners are already prepared to bite a bullet on this basic issue. What advocates of urban rail in the G-L corridor are saying is that it makes a lot more sense to install reserved lanes for rail rather than buses.
It’s possible that there might be a short section of LRT in mixed traffic (one or both tracks). Sacramento’s LRT operates with this kind of compromise (for about a mile along 12th St., approaching the city’s downtown from the northwest), and has done so for the past 26 years — see Advantages of Light Rail in Street Alignments.
There’s a very narrow section on the Drag (especially in the 24th-29th St. area) that might require, totally or partially, something like an interlaced (“gauntlet”) track (i.e., two tracks overlapping each other). This would operate effectively like a single-track section but could be fitted into 5-minute headways and possible shorter. (In Amsterdam, interlaced track is even used with 2-minute headways. More on this rail design configuration in a subsequent posting.)
Further downtown, south of MLK Blvd., it would be logical for the double-track line on Guadalupe to split into two single-track lines — southbound on Guadalupe, northbound on Lavaca St. However, it’s likely that LRT would need its own priority lanes in these streets.
Here’s why: The “Transit Priority Lanes” now being installed on the Lavaca and Guadalupe street pair already seem to present major problems for MetroRapid bus, much less LRT. The reason: Official plans involve inserting MetroRapid into a single lane each way along with well over two dozen bus routes. The City’s own 2011 study of this warned that delays to transit might result. And that’s even before urban rail comes along.
It seems eminently reasonable that LRT would need its own reserved lanes on the opposite side of each street (Lavaca and Guadalupe) from the bus lanes. It’s possible that urban rail could perhaps share lane use with MetroRapid, but not with all those other routes.
Since MetroRapid buses can operate only on the righthand side of the street, these buses (with righthand-side doors) couldn’t share a “lefthand” lane with urban rail on the opposite side of each street. So the solution seems to come down to reserving an additional lane exclusively for urban rail on each street.