The Examination of the Effects of Land Use Development on the Balance of Mass Transit Ridership

The balance of the origin–destination (O-D) ridership distribution is an essential characteristic of a sustainable transit system. However, the existing ridership patterns of transit system in many cities are still off-balance, leading to the inefficient utilization of available capacity. As a result, only one direction is overcrowded whereas the other is not. Many literatures suggest that the transit ridership distribution is generally affected by land use around stations due to the different rates of generated and attracted passengers during each period of time. Therefore, the objective of this study is to verify the effects of land use development according to the Transit Oriented Development (TOD) principle on the balance of the O-D ridership along the transit route, as measured by the discrepancies between the numbers of onboard passengers in stations along a single train line. This study has applied the modified Fluid Analogy Method to reflect the travel behavior of mass transit trip distribution. The results show that, to balance the O-D ridership along a linear and stand-alone transit route, the residential areas should be located near the terminal stations with the sub-residential areas in the interval to shorten the distance of home-based trips. The business areas should be densely situated in the middle of mass transit route, while the retail areas should be located dispersedly all along the route. This study has further applied a proposed model with a case study of MRT Blue Line in Thailand to verify the assumption that the location of the mixed-use project along MRT transit route has impacts on the balance of its ridership. This implication can be a guideline for integrating the mixed-use project development and the land use planning to achieve the sustainable transport in the overall perspective

Traffic Data Analysis on Sathorn Road with Synchro Optimization and Traffic Simulation

Traffic problems have become a plague of the society that cannot be abolished. This work considers the city of Bangkok and its urban road traffic problem, with a particular focus on traffic light control. Managing traffic control by generating optimal traffic signal timing is one of the solutions to reduce the delay at intersections. Synchro is used as a platform to achieve two things in this work. First, to initialize optimal cycle lengths of the intersections on Sathorn road. Second, to assist in the implementation of reversible lane that involves two traffic signal lights in short distance. All of the data are obtained by the technical team of Sathorn Model project, most of which are based on the field work. A comparative analysis is conducted between optimal cycle lengths and the actual signal timing as operated by traffic police from real data collection to see the improvement of travel times in various cases

Increasing Freeway Merge Capacity Through On-Ramp Metering

This research describes field studies of how on-ramp metering can increase the capacity of freeway merges. Some effects of on-ramp metering have been known for a long time. We have known that on-ramp metering can 1) increase freeway flow and speed upstream of a merge; and 2) reduce system-wide delay by alleviating gridlock-causing queues that have blocked off-ramps. However, past studies have not conclusively shown that on-ramp metering can increase the maximum outflow (capacity) of freeway merges. The experiments conducted in the present study verify that on-ramp metering can increase freeway merge capacities. Detailed traffic data collected from videos for more than 30 rush periods at two merge bottlenecks unveil six major research findings: 1) merge capacity diminishes after merges became active bottlenecks; 2) the mechanism of "capacity drop" has been identified and was found to be reproducible across all days and it both sites. By metering the on-ramp in certain strategic ways, the capacity drop mechanism can be 3) reversed; and 4) even averted; 5) such metering strategies can be fully automated using loop detector measurements; and 6) control strategies other than ramp metering also hold promise for increasing merge capacities. These findings provide much-needed information concerning how to control freeway traffic. They also offer basis for more realistic theories of merging traffic flow.

Increasing Freeway Merge Capacity Through On-Ramp Metering

This research describes field studies of how on-ramp metering can increase the capacity of freeway merges. Some effects of on-ramp metering have been known for a long time. We have known that on-ramp metering can 1) increase freeway flow and speed upstream of a merge; and 2) reduce system-wide delay by alleviating gridlock-causing queues that have blocked off-ramps. However, past studies have not conclusively shown that on-ramp metering can increase the maximum outflow (capacity) of freeway merges. The experiments conducted in the present study verify that on-ramp metering can increase freeway merge capacities. Detailed traffic data collected from videos for more than 30 rush periods at two merge bottlenecks unveil six major research findings: 1) merge capacity diminishes after merges became active bottlenecks; 2) the mechanism of "capacity drop" has been identified and was found to be reproducible across all days and it both sites. By metering the on-ramp in certain strategic ways, the capacity drop mechanism can be 3) reversed; and 4) even averted; 5) such metering strategies can be fully automated using loop detector measurements; and 6) control strategies other than ramp metering also hold promise for increasing merge capacities. These findings provide much-needed information concerning how to control freeway traffic. They also offer basis for more realistic theories of merging traffic flow

Increasing Freeway Merge Capacity Through On-Ramp Metering

This research describes field studies of how on-ramp metering can increase the capacity of freeway merges. Some effects of on-ramp metering have been known for a long time. We have known that on-ramp metering can 1) increase freeway flow and speed upstream of a merge; and 2) reduce system-wide delay by alleviating gridlock-causing queues that have blocked off-ramps. However, past studies have not conclusively shown that on-ramp metering can increase the maximum outflow (capacity) of freeway merges. The experiments conducted in the present study verify that on-ramp metering can increase freeway merge capacities. Detailed traffic data collected from videos for more than 30 rush periods at two merge bottlenecks unveil six major research findings: 1) merge capacity diminishes after merges became active bottlenecks; 2) the mechanism of "capacity drop" has been identified and was found to be reproducible across all days and it both sites. By metering the on-ramp in certain strategic ways, the capacity drop mechanism can be 3) reversed; and 4) even averted; 5) such metering strategies can be fully automated using loop detector measurements; and 6) control strategies other than ramp metering also hold promise for increasing merge capacities. These findings provide much-needed information concerning how to control freeway traffic. They also offer basis for more realistic theories of merging traffic flow

On-Ramp Metering Experiments to Increase Freeway Merge Capacity

Observations of two freeway/on-ramp merges unveil the mechanism that causes their capacities to diminish when queues form just upstream. Field experiments at one of the sites demonstrate that by responding to occupancies measured near the merge, ramp metering can reverse this mechanism, or postpone its occurrence, and thereby generate higher merge capacities. Detailed observations at the second site imply that higher merge capacities can also be achieved using traffic control schemes that regulate inflows to the merge from the freeway shoulder lane. Collectively, the findings point to further experiments needed to refine capacity-enhancing control schemes so that such schemes might enjoy wide spread deployment

Increasing the capacity of an isolated merge by metering its on-ramp

Measurements taken downstream of freeway/on-ramp merges have previously shown that discharge flow diminishes when a merge becomes an isolated bottleneck. By means of observation and experiment, we show here that metering an on-ramp can recover the higher discharge flow at a merge and thereby increase the merge capacity. Detailed observations were collected at a single merge using video. These data revealed that the reductions in discharge flow are triggered by a queue that forms near the merge in the freeway shoulder lane and then spreads laterally, as drivers change lanes to maneuver around slow traffic. Our experiments show that once restrictive metering mitigated this shoulder lane queue, high outflows often returned to the median lane. High merge outflows could be restored in all freeway lanes by then relaxing the metering rate so that inflows from the on-ramp increased. Although outflows recovered in this fashion were not sustained for periods greater than 13 min, the findings are the first real evidence that ramp metering can favorably affect the capacity of an isolated merge. Furthermore, these findings point to control strategies that might generate higher outflows for more prolonged periods and increase merge capacity even more. Finally, the findings uncover details of merge operation that are essential for developing realistic theories of merging traffic.

Empirical Study of Ramp Metering and Capacity

Traffic data near the junction of a single-lane on-ramp (with a ramp meter) and a three-lane freeway were measured for six weekdays during the rush and studied. On each of these days, the merge became a bottleneck with queue discharge rates that were substantially lower than the flows that had passed the merge prior to the bottleneck's activation. On some days, these earlier high flows persisted for many minutes. The bottleneck always occurred when inflows from the on-ramp surged in the presence of high flows arriving from the freeway. Often, the on-ramp surges persisted for no longer than a minute or two and a wide range of these surges was observed. The data show strong correlation between the magnitudes of the on-ramp surges and the merge area's outflows that were measured during the final minutes before the bottleneck activations. These short-run outflows were markedly higher on days when surges from the on-ramp were low. This implies on-ramp metering can be an effective means of postponing this bottleneck's activation, thereby prolonging higher outflows from the merge. Further study of the data indicates that vehicles often maneuvered from the shoulder lane to the center lane at locations just downstream of the merge. It appears that bursts in this lane-changing activity were what triggered the bottleneck's daily activations and that these bursts coincided with surges in inflow from the on-ramp. (These lane changes were evidently negotiated by drivers who had just originated from the on-ramp and/or by other drivers over-taking them). Thus, the benefits of metering inflows at this on-ramp seem to stem from the effects this has on limiting disruptive lane changing downstream.Traffic Operations, Ramp Metering, Freeway Bottlenecks, Merge Capacity