Número de miembros y capacitación profesional

As discussed in Chapter 4, many of the accidents associated with Indiana work zones occurred before motorists reached the work zone. Many of these accidents were a result of motorists rear- ending a vehicle that was located at the back of the queue of vehicles waiting to pass through the work zone. Due to the large speed differential between vehicles traveling in free flow conditions and vehicles traveling slowly in a queue, this type of rear end accident is often very severe. To reduce the frequency of this type of accident, motorists must become aware that a work zone is ahead. They must also decrease their speed and increase their alertness because they are likely to be rapidly approaching the rear of a slowly moving queue. To inform motorists of the work zone and to convince them to reduce their speeds, a system of signs should be placed miles in advance of the work zone. This series of signs must be placed such that motorists become aware of the potential for stopped traffic before they encounter such conditions. Such a system was developed and studied under the scope of this project.

As discussed in Chapter 5.2, there is a high volume of traffic that travels the corridor of I-65 near the US 30 interchange. Also discussed in Chapter 5.2 was the queuing that would result when this large volume of traffic was coupled with the lane reduction that is associated with the reconstruction of the interchange. These queues, which are expected to reach two miles in length, would likely produce a high probability of rear end collisions.

In order to reduce the number and frequency of rear end collisions, a series of signs was developed and implemented that would inform motorists of the work zone. These signs were based on concepts that were used in work zones throughout Indiana and Illinois. In this sign plan, the first warning of the construction ahead given to motorists traveling in the northbound direction on I-65 was a sign was placed six miles to the south of the US 30 interchange. This sign, which can be seen in Figure 5-6a, was located before motorists reached Exit 247. This exit provided a route that detoured willing motorists around the construction. As drivers continued north, they would soon see a warning sign, found in Figure 5-7, displaying the fines associated with traffic violations in Indiana work zones.

Following the traffic fines sign, motorists would then see a variable message sign. This sign would display the number of work zone associated tickets issued to date. The number of tickets issued to date would be displayed in a two-phase message and updated weekly. The sign and its two-phase message can be viewed in Figure 5-8. The procedure of displaying the number of traffic fines issued in the work zone was selected because of the anecdotal reports in Illinois of speed reductions when signs similar to Figure 5-7 were deployed upstream of the work zone

a) Northbound Sign b) Southbound Sign

Figure 5-7 Construction Zones Traffic Fines (XIGC-12A,B)

a) Message 1 b) Message 2

Figure 5-8 Variable Message Sign

To display the number of tickets issued to date for the project site, a joint effort was needed between the Indiana State Police and INDOT. On a weekly basis, the Indiana State Police tallied

the number of tickets issued at the project site. This information was then passed on to the graduate research assistants, who updated the variable message signs on a weekly basis.

After the variable message sign, motorists would then pass a series of signs alerting them of the road construction ahead and their distance, displayed in one-mile increments, from the beginning of the work zone. These signs can be found in Figure 5-9. Also included in the series were signs indicating that the Indiana State Police was conducting special speed patrols through the work zone and its surrounding areas. These signs, seen in Figure 5-10, were placed at one-half mile increments following each Road Construction Ahead sign and were ended once the beginning of the work zone was reached.

Figure 5-10 Work Zone Special Patrols (XIGC-14A-I)

A series of signs similar to that found on the northbound lanes of I-65 was also placed on the southbound approach to the interchange. This series of signs was modified slightly from those on the northbound approach because the I-80/94 interchange lays very near the US 30 interchange. Since a great deal of the traffic traveling southbound though the US 30 interchange comes from I- 80/94, the signs were begun slightly south of the I-80/94 interchange so that all motorists would be informed of the construction ahead. Placements of both northbound and southbound signs can be found in Figure 5-11.

247 255 248 250 251 246 249 245 257 256 253 244 254 80 260 261 XIGC-1B (MM 258.4) XIGC-12B w/ $1000 Plaque (MM 258.2) 259 258 VMS B (MM 258.0) 80

XW20-1I w/ 4 Mile Plaque B (MM 257.4)

XW20-1H w/ 3 Mile Plaque B (MM 256.4) XW20-1G w/ 2 Mile Plaque B (MM 255.4) XW20-1F w/ 1 Mile Plaque B (MM 254.4) Begining of SB Taper (MM 253.4) XIGC-14D (MM 250.3) Beginning of NB Taper (MM 251.8)

XW20-1E w/ 1 Mile Plaque A (MM 250.8)

XW20-1D w/ 2 Mile Plaque A (MM 249.8) XW20-1C w/ 3 Mile Plaque A (MM 248.8) XW20-1B w/ 4 Mile Plaque A (MM 247.8) VMS A (MM 246.6) XIGC-1A (MM 246.2) 252 XIGC-14F (MM 254.0) Construction Limits (MM 253.5) Construction Limits (MM 251.6) XIGC-12A w/ $1000 Plaque (MM 246.4) XW20-1A w/ 5 Mile Plaque (MM 246.8) XIGC-14H (MM 255.9) XIGC-14I (MM 256.9) XIGC-14E (MM 251.3) XIGC-14C (MM 249.3) XIGC-14B (MM 248.3) XIGC-14A (MM 247.3) XIGC-14G (MM 254.9)