The way people travel the U.S. 36 corridor continues to improve -- a new study shows a lower proportion of solo drivers and a higher share of carpoolers and telecommuters last year over 2011 -- but population and employment growth in the years ahead could chip away at those achievements.
The 2012 U.S. 36 Mobility Report, released last week by 36 Commuting Solutions, reveals that the percentage of single-occupancy vehicles rolling up and down U.S. 36 between Boulder and Denver last year declined to 68.8 percent from 69.3 percent the previous year. The share of solo drivers on U.S. 36 in 2010 was 70.5 percent.
Carpoolers also ticked up from 8.4 percent to 8.7 percent from 2011 to 2012, but the proportion of people biking and walking in the corridor declined by 0.1 percent, according to the report.
Meanwhile, transit use on U.S. 36 stayed flat -- at 6.2 percent -- but more bus trips were recorded because there was an overall increase in the use of the highway last year. RTD reported nearly 3.1 million transit trips in 2012, compared to just under 3 million in 2011.
Audrey DeBarros, executive director of 36 Commuting Solutions, said the changes reflected in the report are "not dramatic," but she is encouraged by the trend that shows commuters -- for the third consecutive year -- increasingly abandoning their vehicles for other transportation modes.
"The future of U.S. 36 is all about providing commuters with additional options for how they will travel," she said.
Revamp critical to future
Those options should be rich and plentiful once the U.S. 36 Managed Lanes project, which is adding a dedicated bus, high-occupancy vehicle and single-driver toll lane to each side of the highway, wraps up in early 2016.
Work on the $425 million project, which includes a corridor-long bikeway, began last July.
The additional lanes should discourage solo driving, DeBarros said, because they will only allow free travel for HOVs and buses, but will charge a variable toll, depending on congestion, to single-occupancy vehicles. And transit service on the highway will be enhanced with bus rapid transit, a more reliable and frequent type of bus service than what currently exists.
"Because of the infrastructure that is being put in place -- managed lanes, bus rapid transit, carpools, a bikeway -- people will see alternatives to driving that are so much more convenient," DeBarros said.
Nadine Lee, project manager for U.S. 36 bus rapid transit, said her agency projects ridership in the corridor will increase once the new system opens to travelers in 2016 because of the travel time advantages that bus rapid transit provides over conventional service.
But because most transit users in the corridor are "choice riders," and not dependent on the bus for their locomotion, Lee said RTD can't just assume a new fleet of shiny buses and some upgraded bus stations on U.S. 36 will pack them in.
"The change in ridership will hinge on the quality of the service we're providing," she said.
Teri Whitmore, director of regional planning and operations for the Denver Regional Council of Governments, said the fact that solo driving on U.S. 36 is declining proportionally before the highway upgrade has even gone online is encouraging.
"To have a decrease in single-occupancy vehicle use now -- prior to infrastructure improvements -- it shows people are seeking out alternate ways of getting back and forth," she said.
Population growth poses challenge
But increases in transit use and other forms of alternate transportation could be tempered by an expected population surge in the area -- and an accompanying elevated demand for highway capacity -- over the next 20 or so years.
Demographers predict a 28 percent bump in population numbers and a 53 percent jump in jobs in the corridor by 2035. Whitmore said that makes it tough to significantly lower the proportion of solo drivers out on Colorado's highways, including U.S. 36.
Which, she said, makes the U.S. 36 Managed Lanes project, with its emphasis on multi-modal travel, all the more critical.
"The road capacity at this point is not increasing, but the traffic is," she said.