Imagine a future in which travel options like transit, bicycling, and walking would be safer and more practical for more people in the region, and drivers would have the option to bypass congestion and enjoy more reliable travel times on many of the region's highways.
That's the predicted effect of the Transportation Planning Board's "CLRP Aspirations" scenario, an alternative long-term vision for the region calling for a comprehensive network of express toll lanes and bus rapid transit on many of the interstates and other major highways in the region and concentrating future housing and job growth near current or planned transit stations.
The scenario goes above and beyond the transportation improvements currently spelled out in the region's financially-constrained long-range transportation plan -- known as the CLRP -- which, by law, details all of the regionally-significant improvements that are currently expected to be built or implemented between now and 2040.
Express toll lanes are the core feature of the alternative vision. The lanes would give solo drivers who are willing to pay a toll and those who choose high-occupancy alternatives like carpools and buses the option to bypass congestion and enjoy more reliable travel times.
Tolls in the lanes would be higher during peak traffic periods and lower at other times in order to maintain free-flowing conditions in the lanes throughout the day, much as they are now on the new Express Lanes on the Capital Beltway in Virginia.
The network would require construction or conversion more than 900 lane-miles of highway, about 150 of which have already been built for the Intercounty Connector in Maryland and the Beltway in Virginia, or are currently under construction on I-95 south of Washington.
Another main component of the scenario is a 500-mile network of bus rapid transit, or BRT, that would travel on the tolled lanes, making it easier to move more people more quickly and reliably on congestion-free lanes.
The BRT system would connect 70 of the region's housing and job centers with a type of transit service approaching the speed, frequency, and reliability of rail transit. The BRT network would provide much-needed transit service in the region's outer suburbs, where rail transit isn't likely to be financially-viable anytime soon.
Finally, in order to increase the number of people for whom such transit alternatives would be a convenient option, the scenario calls for concentrating more than half of new housing and job growth expected between 2015 and 2040 in mixed-use activity centers near existing and planned rail and BRT stations.
All together, the transportation components of the scenario would cost in the neighborhood of $50 billion over 20 years. Projected revenues from the toll lanes and fares from the new transit service would total around $20 billion, covering about 40% of the total cost of the proposal.
According to the latest TPB analysis, the scenario's three mutually-supportive initiatives, when combined, would result in a 19% increase in the number of commute trips made on foot or by bicycle in the region, relative to current projections -- no small change, considering that many of those trips would have otherwise been made by car on already congested roadways.
Use of bus transit for trips to and from work also increases under the scenario -- by 23% -- and the number of trips by carpools with three or more people jumps by 18%. And although the total overall amount of driving in the region barely changes, vehicle-hours of delay drops almost 27% compared to current forecasts.
The CLRP Aspirations scenario has evolved somewhat over the last couple of years. Most notably, the extent of the toll lane network has been scaled back in an effort to reduce costs and in response to new federal rules regarding the conversion of non-tolled lanes to tolled ones.
The tools and basic assumptions used to analyze the scenario have changed, too. The TPB used its new, finer-grained travel model, which better predicts transit trips and trips on foot and by bicycle, and a more recent version of the CLRP, which includes a few more major transit and highway projects that are expected to be built by 2040.
In addition to analyzing the full CLRP Aspirations scenario, the TPB also studied the effects of implementing just one or two of the three main components without the others.
The analysis found that implementing the network of toll lanes and BRT, absent shifts in land-use, would provide relief from growing delay for drivers and lead to higher rates of carpool use, but would result in higher total amounts of driving and no change in the number of trips on foot or by bicycle.
Simply shifting more housing and job growth into areas around transit stations, absent the network of toll lanes or BRT, would boost the number of walk and bike trips by as much as the full scenario and lead to drops in overall driving, but would also lead to declines in carpool use and provide little relief from growing delay for drivers.
The latest version of the Transportation Planning Board's long-term "CLRP Aspirations" Scenario, which envisions a network of express toll lanes and bus rapid transit and more concentrated growth near transit, would have significant and meaningful impacts on everyday travel patterns in the Washington region. The increases in the use of non-motorized transportation modes and reduced travel delay for drivers would go a long way to making it easier to travel around the region.