An estimated $200 million, RM 620 expansion project — from State Highway 71 to U.S. 183 — is years in the making but ultimately plans call for creating a divided, six-lane road along the busiest stretches. Long term plans could include an elevated road, adding four more lanes along parts of RM 620.
The Texas Department of Transportation hopes to begin an environmental study this spring on the expansion of the southern stretch of RM 620, according to Kelli Reyna, public information officer for the TxDOT Austin district.
South RM 620
“Once we’re ready to begin construction, we would most likely begin working on the portion of RM 620 from SH 71W to Lakeway Boulevard,” Reyna said. “It would be a six-lane divided roadway from SH 71W to Lakeway Boulevard, and a four-lane divided roadway and from Lakeway Boulevard to the Colorado River Bridge (near Mansfield Dam).”
The cities of Lakeway and Bee Cave have both offered to contribute money toward the project, according to Bruce Byron, project manager for TxDOT. It is estimated to cost approximately $50 million for the six-lane divided stretch from State Highway 71 West to Lakeway Boulevard, and $20 million for the four-lane divided roadway from Lakeway Boulevard to the 620 bridge near Mansfield Dam.
“These figures do not include right-of-way costs and are very preliminary, subject to change as we continue to study/design the project,” Reyna said.
North RM 620
TxDOT is also proposing to expand the section of RM 620 from Quinlan Park Road at Steiner Ranch to U.S. Hwy 183 into a six-lane divided roadway, similar to FM 1431 in Cedar Park, according to Byron. That project is likely years away, however.
“There is currently no TxDOT timeline for expanding this section of RM 620 to six lanes,” Reyna said.
One of the challenges for this stretch of roadway is the limited amount of right-of-way that TxDOT owns, Reyna said. She said the amount of right-of-way needed varies widely. For most of this section, TxDOT currently has about 150 feet of right-of-way; however, there are some areas near US 183 where TxDOT has 400 feet and some areas where it has only about 100 feet.
“So you’re aware, 150 feet is very tight for a six-lane roadway with sidewalks, trails, drainage, etc.,” Reyna said. “The exact amount needed won’t be known until final design. We do have a well-defined process, as far as right-of-way acquisition goes. Generally, this phase does not begin until a project receives environmental clearance.”
The entire RM 620 project, from SH 71W to U.S. 183, which is known as the “mid-term improvements,” is estimated to cost a total of approximately $200 million for construction and right-of-way acquisition, according to Byron.
In addition to a six-lane divided roadway, there will also be an eventual need for an additional four-lane roadway on the stretch of RM 620 from U.S. 183 to RM 2222, according to Byron. He gave an update on the proposal at a Jan. 25 community meeting organized by the Steiner Ranch Neighborhood Association.
“In the far distant future, we’re going to have a need in the north section from 2222 to 183 of four additional lanes in addition to the six-lane divided,” Byron said at the meeting. “We don’t have the right of way for that.”
He said the four lanes could be either toll or non-tolled lanes. Possible options would be for TxDOT to expand the right-of-way considerably or, if that isn’t possible, make the four lanes elevated.
“The big decision is how much condemning you want to do for a bunch of right-of-way,” he said. “That’s a study for a future time and a future year.”
RM 620 study
At the community meeting, Byron also updated attendees on the results of a $650,000 feasibility study for RM 620 that was launched by TxDOT in early 2015. The study analyzed the 18.8-mile segment of RM 620 from SH 71 to U.S. 183 by breaking it up into six individual sections and analyzing data such as crash data, traffic counts and improvement options for each section.
RM 620 crashes
The study found that between the years of 2010-2015, there was a total of 1,908 crashes on the entire stretch of RM 620. The majority of those crashes, 556, occurred in section 5 in Lakeway.
There were 398 crashes during that time period in Section 2, running from Anderson Mill Road to RM 2222, and 285 crashes in section 3, which runs from RM 2222 to Quinlan Park Road.
“One of the most interesting things that happened when we did a survey of people, users of 620, (is that) 19 percent of the people taking that survey had been in a crash on 620,” Byron said.” That’s an astounding figure.”
RM 620 traffic counts
TxDOT also collected 24-hour traffic counts for each section in 2015.
Section 2 from Anderson Mill Road to RM 2222 had a 24-hour traffic count of 43,400. Section 3 from RM 2222 to Quinlan Park Road had a 24-hour traffic count of 44,400.