N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b o o u u t t c & Transportation Planning C C o o n n f f e e r r e e n n c c e e 2 2 0 0 0 0 5 5 D D R R February 2005 Cheryl Banigan, Chief, Traffi A Local Perspective Jeffrey M. Stratmeyer, P.E., Chief Engineer A A F F T T Roundabouts in Harford County, Maryland Roundabouts in Harford County, By: N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b they are landscaped, a . Currently, there are the center islands are o and is home for over o u u Constant Friendship Blvd. t t C C ve been added on the approach o o rbing around the perimeter and , increase intersection safety, n n roads, and started using f f e e r r e e n n c c e Constant Friendship Business Park, at the e Constant Friendship e e but the signs can not restrict sight distance majority of them have a 15’ wide travel lane, majority communities. Before communities. 2 sight distance and that the root systems of the sight distance and that the root systems 2 with the curbing around the island or with the trances into BJ’s Warehouse, and one access to 0 eter center island that may be landscaped. We 0 ladder trucks. Several of h are located on Harford County controlled h are located on Harford County ads where they are located 0 more Metropolitan region Metropolitan more 0 Future entrance Future entrance 5 5 Truck access e County’s Grounds Maintenance Supervisor to ounty drivers to the concept of roundabouts. drivers to the concept of roundabouts. ounty D D R R A Local Perspective A A F F roads are constructed with cu to control intersection capacity T T eakaway structure. Reflectors ha business or community is permitted to install a sign indicating business or community is permitted y maintains over 1,000 miles of over 1,000 miles y maintains t was constructed in th Roundabouts in Harford County, Maryland Roundabouts in Harford County, BJ’s entrance landscaped and maintained by local businesses or landscaped and maintained and reviewed by th be submitted plan must ensure the proposed landscaping will not restrict plantings will not create a maintenance problem truck apron. Additionally, the that they sponsor the landscaping and maintenance, be constructed as a br and must visibility. sides of the splitter islands to improve have a design speed of fifteen miles per hour. The have a design speed of fifteen miles a 15 foot wide truck apron and a 40’ - 50’ diam changed our signs on the outside edge of the splitter islands to only install flex posts at the request of the fire department to accommodate All of the roundabouts on County Maryland is part of the Balti Harford County, end of a cul-de-sac in 1995. There were two en the adjacent lot proposed from the cul-de-sac. We felt the roundabout would effectively control access to the lots and introduce Harford C The County’s first roundabou 225,000 residents. The Count roundabouts in 1995 as a means the residential integrity of the ro and maintain Harford County, 14 of whic 16 roundabouts in under design. roadways and an additional three N N a a t t i i o o n n a a l l R R o o u u n n d d a a interchange and US 1 b b o o u u t t C C respectively. The ADT on o o wn of Bel Air. The population e 24 between I-95 and the Town n decade, and is expected to n f f e a missing segment of the roadway a missing e r r e 24 and Business Route 1, the e e n n c c so connect to MD Route 24 are projected to e e l communities, two elementary schools, a a four-legged intersection that also includes Currently, the ADT on MD 24 just northwest Currently, the 2 2 the corridor) is constructed by a developer and the corridor) is constructed siness becomes a useable commuter route. a useable commuter siness becomes between I-95 and the Town of Bel Air. The was decided to consider using them in other was decided to consider using them MD 924 between the I-95 0 0 a major roadway was on a major collector road, roadway was on a major a major 0 0 5 5 D D R R limited commerciallimited developments concerns regarding Tollgate Road: concerns regarding Tollgate A A road that parallels MD Rout F F ate Road are 22,700 and 10,800 increased by 34% in the past oximately five miles to the To five miles oximately T T and MD 924 veer northward after their intersection with MD 24 is complete between MD Rout is complete new hospital, a new library and new hospital, Tollgate Road is a collector Tollgate Road primarily connects residentia Tollgate Road primarily of Bel Air. have failing levels of service. intersections with other collector roads that al Once Tollgate Road • • locations. The first location considered along Tollgate Road that parallels Maryland Route 24 Tollgate Road Maryland 24 corridor is part of the designated growth area for Harford County. intersects Maryland Route 24 just north of I-95 at MD 924. Both Tollgate Road and then parallel MD 24 for appr in the MD Route 24 corridor has increase by an additional 19% by the year 2020. of the I-95 interchange is 64,800. The roundabout worked well and, as a result, it The ADT’s on MD 924 and Tollg Tollgate Road is expected to increase to over 18,000 when of (approximately 1,500’ long and in the middle the entire roadway between MD 24 and US 1 Bu There are 8 traffic signals on MD 24 and 10 on Business, which raised the following N N a a t t i i o o n n a a l l R R o o u u n n d d rketplace Drive, in a a nd at least one more nd at least one more s estimated at about b b o o vehicle accidents; one u u of roundabouts was t t C C effort, five roundabouts have Residential development Residential development o o e roundabout was constructed as e roundabout n n f f e e 24 and MD 924 may consider r r e e n n c c o more are in design a o more velopment to the east and also connects to velopment Road corridor was at Ma e e the roundabout and wa s or to construct a roundabout for his access ketplace Drive s, including the relocation of several large s, including the 2 2 0 0 void impacts to the existing residents on the right void impacts cation. Two were single got stuck in the island in the middle of the middle in the island in the got stuck 0 0 r intersections…a series 5 5 acter of Tollgate Road, while reducing speeding and ly $220,000. The roundabout option actually D D R R A A eeding down Tollgate Road. ying attention, hit the curb of the splitter island and blew out ad corridor. As a result of that F at delayed traffic on MD F T T ite was given the option of installing a signal with additional ite was given the option of installing a signal with additional Tollgate Road/Mar the less expensive option and th Commercial development development Commercial bypassing those delays by sp Concerns were expressed th • In an effort to maintain the residential char controlling the volumes of traffic at the majo proposed for the entire Tollgate Ro driver was under the influence of alcohol and roundabout and the other wasn’t pa a tire. There have been 3 reported accidents at this lo The first roundabout constructed along the Tollgate The first roundabout been constructed along Tollgate Road since 1996, tw is proposed. 1996. Marketplace Drive accesses a commercial de MD 24. The developer for the s road widening to accommodate turning movement onto Tollgate Road. The signal and improvement would have cost approximate utility poles roadway on the approach to narrowing the involved $92,000. The developer chose photo below. Note the offset to a shown in the side of the picture. N N a a t t i i o o n n a a l l R R o o u u n n d d a a b b complete between MD complete o o veloper who was adding u u t t C C ve been a factor in several o o ted by the County to ted by the County to about at Tollgate Road and n n 3,000 on Singer Road. The ADT 3,000 on Singer f f e e r r e e n n c c e and to eliminate the concerns associated e ad. The vertical curve contributed to reduced ad. The vertical curve contributed is expected to increase with additional 2 2 e Road when the road is Tollgate Road for approximately ½ mile to the Tollgate Road ½ mile for approximately 0 0 l traffic flows warranted the inclusion of more l traffic flows warranted the inclusion of more also constructed by a de road in the County and there have been no with the Marketplace Drive roundabout, the 0 0 5 5 D D R R e roundabout was sugges e roundabout A A F F r approximately 12 - 18 months before deciding that the r approximately 12 - 18 months T T itional installations.